Tag Archives: Cannabis

The Fridgegrow – closed loop growing with co2 support

Weed in a fridge

Flowering cannabis in a fridge
Cannabis that was grown in a fridge using the fridge grow

So when people think about starting to grow weed, they usually look at it from the beneficial side: It would cost less than the shady park vendor or the dispensary in nearly every case, especially when quality is taken into account. The overall quality is more controllable. Plus: In a world with PGRs, terpene spray, brix or artifical cannabinoids its still recommended by me to rather grow at home, than buying stuff simply because the packaging looks shiny.

The fridgegrow controller tries to fill a gap in the homegrow segment. Its not a fullblown all-in-one closet where you have little to no options in terms of light or nutrition, but its also not a tent, where you usually have to deal with environmental values as they come. When the door to the fridge is closed, its not possible to exchange air or even water from inside the fridge. (disclaimer: this is only half-true, but for simplicity we will assume this for that article.) You will have to bring some ingenuity into the operation!

The fridgegrow setup uses a few key elements to keep the environmental values in check:

The fridge

A fridge is able to lower the temperature inside its volume, without exchanging air inside the fridge. Lowering the temperature lowers the possible maximum of moisture the air can hold, water will condense on the cold backwall of the fridge and trickle down…
The fridges total power has to “work” against the grow lights total power, and therefore should be able to “outfreeze” the heat.
The fridge is not included in the system. I recommend to buy a beverage fridge for commercial usage with a closed front. You want to keep the light out. Make sure, that the fridge has as much power as you can get. Its easier to hold the values this way. Heres a fridge from amazon with a clear front, that has to be masked first.

A small heating element

A heater is able to work against the fridge to keep the relative humidity up. In a perfectly dialed in fridgegrow setup the heater will almost never run during the light-on phases, because light and fridge should cancel each other out AND holding onto certain humidity levels while doing so. This is also dependend on the total amount of water inside the fridge chamber.

The perfect light – crescience modular fluXengine LED built

There is no reasoning here for anything else than a high efficient LED setup. No asian amazon light or HPS light will be acceptable if your plan is to grow cannabis in here. Make sure you are able to remove the driver and try to place it outside the fridge. One thing I love about that built is, that I get to chose the light, and its not prebuilt in here!

LED grow light and flowering cannabis in a fridge
Crescience DIY LED setup -3x fluXengine board-style repping the Samsung LM301B chips aswell as a Meanwell – ELG-150-24A

For my fridge I have chosen a modular LED solution by Crescience. Crescience is known for their modularity and compatibilty to standardsized aluminium-framing. Its super-easy to build and you can actually achieve tailored photon-outputs for every system ever.
I am running 3 of their fluxEngines (link goes to the updated lm301h version) powered by a Meanwell ELG-150-24-A Driver.

Some thoughts about the fridge-light-interaction

The principle of continuity says: What goes in has to come out. This is true for everything that has a flow to it. In the case of the fridge one puts energy as heat into the system via the grow light and the heating element. The vapor-compression element on the back of the fridge is able to get heat out of the system and will transport it away through the heatpipes on the back of the fridge. Thats also the reason a fridge is hot in the back and cold inside. Our limiting factor for our light is the fridges compressor efficiency. If our fridge cant transport the heat away through its compressor the inside of the fridge will heat up endlessly, which will result in darkness since the controller will always try to save the plants, no matter if its “daytime” or “nighttime”. This means we need the most efficient and cool running light setup in here. A commercial beverage fridge for business will have a power draw between 90 and 150W from the wall. The light you use should draw a bit less than that.

Air circulation

Small fans directed at the back of the fridge are also an important element in this setup. It keeps the watercycle running smooth and steady. I have chosen Arctic 120mm PC-Fans . I connected them via a 4-way 3-pin fan-connector in parallel and a 12V/2A powersupply. If you are not sure about that, ask an electrician how to wire it.

fans in front of a fridge grow
Arctic PC-Coolers keep the air circulation going in the fridgegrow.

vertical nets or other vertical scrog systems

Keeps your growth in check! I had a few leafs touching the backwall of the fridge keeping the water from dripping down. This results in considerable pieces of ice in there, although its almost 30°C while the lights are on! Ice is bad. It binds water and takes it out of the waterloop.
I gave my plants only 4 glasses of water – in 67 days of growing. And this is a problem.

Scrog in a fridge
Basket-ScrOG system – the grow-space is very limited, so you have to expose as much buds as possible to direct light.

Feeding plants in a closed loop system

While a small windowsill plant doesnt need much to stay green and vital, cannabis under a blasting sun-replacement will transpire significantly more and will therefore have a much increased need of moisture. The trick is to catch the condensing droplets from the back of fridge and guide them back into the pots. Even if youre not able to do that perfectly, the water will still stay in the system, because of the fridges isolation. All you need to do is to close the small hole in the lower back of the fridge, where drops usually get vaporized through the compressor on the back. We dont want that, so we close the loop with a sheet of metal, guiding it back into the pots. This also has disadvantages: Im used to give diluted water-nutrition solution to my plants. Bio Bizz usually is diluted in a way that about 1-5ml of nutritional concentrate gets mixed with one liter of water. This is of course only true for system where the soil can dry out a bit and this wont happen in a fridge setup. You have to put in higher concentration (same amount of nutrition but on a glass of water) or you go for solid nutrition like greenhouse feeding or pre-grow formulas like Biotabs Organics.

I hold my plants in 3 gal smart-pots. Pathological amounts of greenhouse bio bloom and some biobizz was given, but i wasnt really able to conquer the ramping deficiencies my plants developed.

nutrient defincency on cannabis plant in fridge
Leaf discoloration and washed out leaf-tips: this plant was craving for nutrition.

Controlling CO2 – hacking sodamax/sodastream bottles

This is the first setup I was able to make use of extra CO2 inside a grow room. You first need to buy a CO2 bottle, that gets usually used for gassing up beverages mixed together in the kitchen. This bottle is under a standard pressure of about 6 Bar. The first connection has to go to a pressure-bottle adaptor. This adaptor is then connected to a pressure-reducer unit. The reason for that is the next element: its the actual CO2 valve that lets CO2 flow into the system: The CO2-magnet-valve that can be controlled electrical by the fridge-grow controller.

pressure limiter system
CO2 pressure-reducer: left you can see that the bottle-pressure is below 1BAR, so it will have to be replaced soon! On the left is the pressure measured, that lies between the magnetic-valve and the pressure-reducer: theres still CO2 available! But a second bottle would come in handy…

The Fridgegrow-Controller

This is the heart of the system. Its basically a mixture between a server (with a UI to check data and setup the environment ) and a controller. In principle the controller is just turning bluetooth-powerplugs on and off whenever temperature, humidity needs to be dialed in, lights to be turned on and off, or to open and close the CO2 valve. The system is pretty much plug and play and can be setup even if youre not really techsavvy.

fridgegrow controller
The fridgegrow-controller . In the back you can see the droplets of water that will eventually flow back into the soil. On the right-hand-side of the controller is the casing for the temperture and humidity sensor.

The controller will react to different parameters that are more or less dependent on each other. It will find a more or less stable cycle dependent on set values and the amount of water in the system.


The fridge reacts to two central reading: humidity and temperature. It will turn ON when ever the current humidity rises above the set value AND the temperature is high enough.
In this case that means that the temperature is at its set level or at max. 2x below the set hysteresis. A hystersis-value is the margin a value can go above or beyond.
So if you setup the fridge to hold a temperature between 24°C and 28°C (Thats 26°C with a hysteresis of 2°C) and relative humidity between 65% and 75% (set 70% with a hysteresis of 5%) the fridge will only start running when the humidity exceeds 75% while the fridge is between 22°C and 26°C.
The fridge will turn off when values below 70% relative humidity are reached or the temp drops below 22°C which is 2x the hysteresis. You can see easily that reaching the right relative humidity is dependent on the amount of water in the system. The fridge will never get below certain values if theres too much water to condensate.

Light control

This one seems easy: It just switches on and off at set-times.
But the system is also inhibitng fail-save measurements to save the plant. And heres the tricky part. The fridge can actually overheat while its trying to find a cycle, and thats a nono for the controller. It will turn of any heatsource that exceeds the global temperature limit. And thats the set-tempreature plus 2x the set-hysteresis. So in a running system with a 26°C ± 2°C the light will go out when ever the system breaks the 30°C limit to save the plants.
This can actually happen when theres not enough water around to keep humidity high: the heater will run longer to increase the amount of water in the air and will hit the temp-limit before the humidity levels can be reached. This will perodically lead to on/off cycles of the lights! So be aware of your cycles!

CO2 and Heating

CO2 is kind of entangled from the rest. The gas wont interfere with temperature and humidity and will be dialed in by the controller according to the set value and hysteresis.
The heater is your last bastion to figure out your values/moisture levels in the system. If the controller thinks, that a the heater needs to run WHILE the lights are on you have one of two problems:You need less water in the system!

The heater only reacts to temperature, so it will only go on, while the temperature drops too low. This can only be the case when the fridge runs too long against the light, trying to reduce the humidity. If you can dial up the light to create more evaporation the fridge will have a harder time reducing the temps, keeping the heater off.
If theres no use to it, and the humidity levels wont fall of with a constantly running fridge and a constantly running light, you have too much water in the system, so try to remove some. But this is basically the equilibium you want to achive: Running heater only when the lights are off, trying to get a stable water-humidity-temp equilibrium going.

The fridgegrow-app

One last word about the fridgegrow-app. To set everything up you need to be connected to the controller via the app or the controllers local webiste. If you dont connect the controller to your local wifi (which i recommend for safety concerns) you have to use the internal wifi from the controller. The controller guides you through the first setup of the remote-power plugs and is pretty easy to use with a standard UI and graphs of the sensor-data. Perfect for a nerd-grower like I am! In the graphic below you can see that i turned on three graphs, temp, hum and CO2. In the graphic you can see the exact moment when I opened the fridge at 19:15 or 7:15pm. the humidity and CO2 drops significantly as I pulled everything out of it, when I opened the door. The CO2 controller will turn on immediatly while you can also see the heating element tries to work against the fridge to keep the temp low.

screenshot of fridgegrow app
View through the fridgegrow app – setup your controller, check your values – remotely

Wrap-up: Should you buy a fridge grow?

For the beginners: Yes, its possible to just watch and learn with this system. Its really an accomplishment and a good amount of work to have it running stable for the first time, but you will be given a system were you have full control of every aspect of a run, while still be able to hold smell and noise in place.

Its for the nerd who grew weed in the past, but maybe dont want to have the whole fan/tent etc. infrastructure in his family home anymore. Maybe you want to get most of a limited space? This system got you definetly covered. I will try to harvest 100g dry regurlary out of there, and this should be enought to supply a single consumer out there and I am convinced that this system is working since I got my first 60g of Humboldt Seeds OGKZ out of there and it was a more than decent smoking experience. Welcome to the 21 century growers!

The Pro Grows: Blue Gelato by Barneys Farm – The 100l experiment

Why you should grow Blue Gelato 41

Derived from Thin Mint Girl Scout Cookies and Blueberry the Blue Gelato is another US based import to the European market under the distribution of Barneys Farm. The strain contains that mainly sweet and citric taste that Gelato is known for. Underlying with OG and Blueberry flavors you will get a …

(here I rolled a fatty to experience it another timer)

38°C on my balcony. The wind feels like a desert or caribian breeze. It all started with the selection of the particular flower. I decided to use one of the many top headbuds. The curing process was only three weeks in, the flower was as gluey as it gets and showed an incredible trichome density.

The effect delays into the second or third hit, subtle first but exponentially transforms to a truckload into the back of your head very quickly. The high is longlasting and top heavy. Side effects for me are a dry mouth and a big urge to eat some hot and spicy food.

(here I took another break to rest on the couch with some ice tea)

Items and tools

TL;DR – Blue Gelato 41

  • Strain: Blue Gelato 41 by Barneys Farm
  • From seed to weed: 141 days (veg 84 days, flower 57 days)
  • Wet harvest weight: n.a.
  • Final Dry yield: 244 gr (8.6 oz, single plant)
  • Effect: Strong, head heavy, numb mouth, clouded mind, psychedelic
  • Taste: sweet, OG, pungy

The Grow

Germination and Seedling Stage

When growing from seed you should always germinate more seeds than the actual number of plants you want to grow. Since I wanted to have one single huge plant I germinated two seeds and simply used the first one to show up as the main plant.

cannabis seeds
Blue Gelato 41 seeds

After about 0.5 cm of the initial root showed up, I put the seedling into a 3 gal smartpot with a fresh batch of BioBizz Lightmix. The first two weeks of a grow are always slow and boring: You dont really need to do anything but sit and watch. I kept the soil moist with my sprayer to prevent the seed from tilting from too much water. After the stem was strong enough, I turned to my usual watering schedule. This is also the point where I first give the seedling external nutrition. Lightmix already comes with a good amount of plantfood but for the remainder of the vegetative I gave her 2 ml of Bio Grow and 2 ml of Bio Heaven per liter of water. As usual I lowered the pH of my water dwon from 7.8 to the region bewtween 6.2 and 6.5.

Small cannabis plant in soil
Seedling a week after germination

Vegetative Stage – the long training

As you might know, I count the seedling stage into the veg stage. So the day my seeds get hit with water, I start counting veg days.

After 18 days the plant was ready for the top. I topped her once with intend and a few times by accident. I topped the plant right above the second node, so I ended up with four main branches, that will be trained outwards.

Cannabis plant in vegetative growth
After 18 days this plant was ready for an early top
topped cannabis plant
4 tops are left to be trained outwards
topped cannabis plant with LST applied
After three days the tops are ready for the bend!

Training setup is done! For the rest of veg I just had to train the shoots outwards again and again. four weeks into vegging I transplanted the plant into its final container: A single 100 liter unit! I decided to give her eight weeks to root through this volume.

Transplanted cannabis plant
Blue Gelato 41 after one month since germination in its final pot.

For this particular plant it was necessary to remove several side branches while it got trained further and further. The internodial distance was just to short, and even with this premeasurement the plant ended up being a nasty bush nontheless.

cannabis plant in a big pot
Bushy plant that needs some trainin…. (6 weeks old)
cannabis plant in training
…and after appyling LST (same day)

I wanted to play that out as far as possible and ended up with a structure that looked more like a weird piece of art than a plant.

heavy LST applied to plant
Heavy LST applied to a cannabis plant results in this structure. (8 weeks of veg)

The branches and the stalk are getting fatter by the day after 8 weeks of veg. The plan was to let her grow to the walls of the grow room and then upwards to encourage a bit of stretch once shes sent into flower.

cannabis plant and a ruler
My plant is 15cm tall after 10 weeks of veg.
upskirt shot of a cannabis plant
This shot shows what you have to deal with when doing something like that.

A few words why this method of growing cannabis is actually pretty dumb: So my grow room would be on top when it comes to economical grows. I use very efficient LED lights and do not bother with AC units or anything that impacts my electricity bill alot. I am still growing with under 400W of total power. But having a plant in this environment for that long kind of kills the idea of being economical here. Time is an important factor when it comes to economical growing, and what was done here was the opposite. The grow itself took close to 5 months to finish, while its possible to harvest more in just 3.5 months.

Flowering the beast

After 84 days of veg I pulled the trigger and started flowering. The branches did not really hit the walls of the grow room, but I thought the flowering stretch and a little bit of spreading would take care of that. Note that I defoliate pretty conservativley before flowering, which cant be seen here exactly, but my goal is, that every top gets direct sunlight.

huge plant
Blue Gelato 41 starting to flower.
detail shot of early flowers
Cannabis flowers in the earliest stage of development.

But I was wrong here: the plant had to support about 50 to 70 tops and stretching was not something she wanted to take care of. My assumption is, that the potential to stretch decreases heavily with the amount of top to put energy into to stretch. I got about 5 cm extra height overall, and thats it.

With the development of flowers, the plant now needs different supplements. So I switched from grow to bloom nutrition according to the BioBizz nutrient schedule sheet. I watered the pot with 10 l of water every 3rd or 4th day. Hitting day 21 of flowering I went for another round of defoliation, but I figuered out soon enough that this would not be enough for that lady. She kept putting out leaf material by the day, and I could grab handfuls of leafs far into the flower cycle. Most of the leafs on the back of the plant could not be pruned because I simply could not access that area at all…

cannabis flowers in development overview shot
Blue Gelato 41 in flowering.
macro shot of cannabis plant in early development
Resin production began early and heavily on that pheno.

Whenever you hit week six of flowering theres not much to do but checking trichomes and soil moisture.

maturing cannabis plant
Flowers of Blue Gelato 41 near the finish line

Although I had to deal with leafy colas the resin production on that strain is insane! After only 20 days of flower the colas were packed with trichs and after only 46 days I could already see trichomes turn amber.

trichome shot of cannabis
Day 46 of flower and the trichomes are already turning amber and are mostly milky. This one will be a fast runner!
cannabis plant closeup
Blue Gelato flower

Harvest, Drying and Curing

macro shot of harvestready cannabis
Brown pisitls, milky trichomes, and a good portion of amber ones: this lady is ready for harvest

So after only 57 days, six days before the harvest window given by the breeder, I decided to cut her down. Not only because she was ready, but I had to fight high temps in the grow room, and I did not want to risk any mold since that bush was so dense! pulling out a 100l pot out of that room was a pain.

bushy cannabis plant
The leafy backside of the plant, that I never had the chance to defoliate.

I decided to dry trim this time. So I cut away most of the fan leafs and hang her up branch by branch. After 7 days of this initial drying it was time for manicuring. This is mostly done by removing everything thats not flower material. But since the resin production of that one was so incredible dense I decided to keep a lot of sugarleafs on her. It was a rather experimental run in the end and I would not do it like that again, but a worthwhile experience!

cannabis dried and ready to smoke
Curing Blue Gelato 41


Topping is an invasive training method. Contrary to Low Stress Training a plant needs a significantly longer recovery time from an amputation, which sounds reasonable.

Timelapse of a topped cannabis plant

As you can see, the plant is developing more than one main branch. This happens due to the amputation.

The right moment to top – mainline or spreading

How to top cannabis plants
The topped plant has already established very noticable side nodes. These will be the new main Branches

The right moment to cut of the head of a young cannabis plant is to choose carefully. What to you want to achieve? If you want to spread out her sideshoots you can wait until two weeks before flowering to cut off the main. The plant will distribute more energy and growth into the sidebranches which will develop much better after that. So you end up with more thicker branches at even height which will also optimize growth overall. Growers who do that, like to top a bit later into the vegstate (after the 5th node) and refrain from low stress training in the way to let the shoots go upwards.

Example of a topped autoflowering plant
Autoflower that got topped without mainline. source

Mainlining your plant has a different approach: Its more of an artform and maintops will be developed in a more symmetrical manner. The topping has to happen much earlier in is my favourite approach to HST or high intensity stress training. It combines HST with LST very early on in the life cycle and gives you the ability to guide the growth of the plant in a more detailed fashion. It also let the plant stay small and bonsaiesque which is favorable for small grow spaces with low heights.

Mainline branches
Plant that got topped and put under LST at least twice. This results in 2^2=4 shoots.

Mainlined plants are split up immediatly with next to no internodial growth. That results in a distinct number of tops: If you cut away the mainshoot n times you will end up with 2^n mains.

triple mainline
A plant that got topped a third time, resulting in 8 main shoots.

Pros and Cons of topping

First of all topping costs time. Flowers need to heal up of that for about two weeks before you can think of switchting them to flower and establish a healthy branch structure again. You will end up with a more even canopy, can bring the light lower and will ultimately get more yield since more buds are in close proximity to the light source. Mainlining takes even more time than just a single top, but you will be able to shape your plant in various ways because all fresh branches are still young and flexible.

My recommendation: Take your time and let her veg for 2-4 weeks longer. You wont be disappointed in the end.

Topping Autoflowers

Yes, topping autoflowers is definetly possible. The best strains to try this in are the ones with a longer life cycle like most sativa dominant strains. The moment of the amputation has to be crucially timed tho. If you think the plant is already about to strech or shows early signs of sex, you should refrain from it. The time window to properly top an auto is pretty thin. Be careful here. But as I said: Its worth it in the end.

A mighty cannabis flower
If done right you will end up with a massive canopy of donkey dicks! (This is not an autoflower.)

The Pro Grows: Lemon Zkittle by Dutch Passion

Why you should grow Lemon Zkittle

With the on-going legalization in the US and Canada many awesome crosses have emerged from the vast number of varieties developed in that part of the world. Next to OG Kush, Cookies or modern strains like all the Gelatos there is one name to be heard all the time: Zkittlez.

Lemon Zkittle by Dutch Passion is a derivate from Las Vegas Lemon Skunk and cupwinning Zkittlez relative. Her THC content exceeds the 20% as all modern strains seem to do. The phenotype I have grown shows some differences to the given description by Dutch Passion due to the conditions she was in. I grew her in winter, so at lights-off the ambient temp in the tent could drop somewhat under 20°C which gave her a little purple shade in the end. I also used prefertilized soil by Kanamu Pacha and solid nutrition in the form of the GreenHouse Feeding Bio Line. So no bottled nutes were used this time, only organic material that has to interact with the medium and water.
The resin production of the Strain is outstanding, and you will end up with a carpet of trichomes on the leaves and flowers.

Mature cannabis plant
Lemon Zkittle seven days before harvest showing amazing resin production.

Items and Tools

TL;DR – Lemon Zkittle

  • Strain: Lemon Zkittle by Dutch Passion
  • From seed to weed: 143 days (veg 76 days, flower 67 days)
  • Wet harvest weight (wet trimmed): n.a.
  • Final dry yield: 188 gr (6.6 oz)
  • Effect: extreme strong, head heavy, paranoid, numb/dry mouth, long lasting
  • Taste: Due to some fuckups by me on the hay side, subtly lemony, next to no Zkittles flavor

Grow it…
…if you like US resin coated sugar strains.
…if you like lemon flavours.

Don’t grow it…
…if you like to mainline your plants.

The Grow

Germination and seedling stage

I used my usual method to germinate two seeds in a paper towel. I used pH-regulated water (pH of 5.7 to 6.0) and let it soak in water until saturation.

items for germination
Items im using for germination: Bowl with water, paper towel, seeds (in the middle), a jamglass lid, pH-meter
seeds on a papertowel
Put the seeds on the paper…
wet papertowel in a jar lid
Let the paper soak in water as much as it can, and add some additional water to the lid.

This way, the seeds start with a lot of moisture. Put the ghetto-petri dish in a warm (around 27°C is perfect, but not necessary) and dark place and check it every 24 – 48 hrs. After 3-7 days the seed should be ready to pot when the inital root is between 0.5 cm and 1 cm long. The soil should be at least a bit moist at this point, but not dripping wet. Make the root look for the moisture and stretch to it. Place it about 1.5 cm deep and put some loose soil above it.

cannabis seedling in soil
Lemon Zkittle Seedling looking through the soil.

After a couple of days the seedling should break through the soil. In this stage the seedling is most vulnerable. I recommend to just let it be, and keep the area around the plant moist. I use a water sprayer for that. In this time I wet the soil every day. The stem and roots are not strong enough to keep the plant standing if the soil is too wet, so prevent that. Its not lethal if it happens tho. After some days the stem will be strong enough to use my flood watering method again. Since the roots need time to grow through the soil, you can take 5l of waters for the 30l of soil and you will need to water only once a week for starters.

Vegetative Stage: Training!

14 days after germination the plant was ready for the first top at the forth node. I wanted to achieve a mainline of four branches going in perpendicular direction and keep the secondary branches coming out of them for a massive bush.

topped cannabis plant
Cut of the main top of the plant on day 14 after gemination.

The mainline was done via the metal stakes im using for a while now. The branches keep growing horitontally while second nodes develop more heavy since the plant wants to compensate for the hassle of the main branches. I will never

LST applied on cannabis plant
3 days after the top, the plant was ready for LST.
LST reaction from the plant
Lemon Zkittles reaction to LST

The LST is applied everytime the plant grows back pointing upwards. This can take a lot of time, since i wanted to fill up as much area as possible.

reaction of the plant due to LST
A new round of LST is applied (left). After only three days the plant is ready for the next round.

This method will result in a great amount of nodes and leaves. Its your job to decide which node you keep and which one to cut away. Usually I keep mine for a week or two to determine if the plant is distributing energy to it. This will be adressed later when it comes to lollypopping in flowering.

bonsai cannabis
LST keeps the plant flat in check.
LST and clear bottom of plant
Keep the lower branches clear, to reduce larf/popcorn growth in the flowering stage.
stalk of cannabis plant
The stem will grow to a big stalk the longer you veg, and the more room there is for the roots.

Flowering Stage

When the plant uses up most of the grow area its time to send her to the flowering stage. Note that this is only possible if you are using regular or feminized plants and not autoflowering ones.

cannabis plant in full scale
Lemon Zkittle in early flowering filling up the space.

This plant was in veg-stage for 51 days before flowering. In the first 21 days of flowering I let her stretch out and removed some leaves here and there, but nothing major.

stretching plant
Stretch of the Lemon Zkittle is pretty moderate. The mainlined tops are clearly outstanding in height.

On day 21 I removed a lot of fan leafs and cut away some poorly developed tops. The reason for this is, that I want to have well developed main tops instead of a massive amount of larf. From that point on there will still be a fan leaf found casting a shadow over a bud once in a while. Rule for removing leafs: If a leaf keeps direct light away from a bud, it has to go.

Rule for removing entire tops: If its way below canopy level and poorly developed, it has to go. Disclaimer: I should have cut more on that plant. The plant has about 50-60 tops in the end, and the pot was way too little to distribute energy to every single one of them properly.

cannabis in early flowering
Bud development on the numerous tops I left for flowering.

After day 21 i basically just sit and watch the plant thrive. Keep her fed and watered and watch out for deficiencies. This plant was grown fully organically and i stopped actively giving nutrition around week 5 of 9.

cannabis maturing in flowering
Trichomes are highly reflective and look very frosty in the middle of the grow.
single cola of cannabis plant
Lemon Zkittle cola in flowering. This structure with no space in between buds is a very desireable property.

In the course of the grow the Lemon Zkittle developes an amazing trichome density. This is always a good sign! The trichomes start with clear appearence.

macro shot of cannabis plant
Macroshot in the middle of flowering. The trichome denisty is top notch. The trichomes are mostly clear and the pistils are pointing upwards. Maturity is still far from reached.

After seven weeks, the plant shows visible signs of deficiency. Since the life cycle would be over after week 9 to 10 and im using organic nutrition I refrained to use more of that on her and let her fade.

full scale flowering plant
Late flowering: The leaves turn yellow
macro shot of trichomes
Mature flower: The trichome start to change from cloudy to amber. Its time!

After 8 weeks the trichomes were mostly cloud, while a good portion already started the transition to amber. I had her in the closet for another week and harvested her on point after 63 days of flowering.

Harvest and curing

Harvesting such a large plant is not always easy. She had such a large number of tops that I had to do the whole ordeal in two days. I let her dry off about 10 days as a whole plant before I went to dry trim and curing. I aimed for 300+ gramm but only came out about 60% of that. Thats fine for a single plant, but I think I screwd up the training process and was a bit less patient for the flowering switch to happen. I cured her for about a week with burping and paying close attention to the feel of the product. After that I used the C-Vault and Boveda Packs to further store the goods in a perfect environtment. In the end I would like to encourage you to tryout that strain. The trichome density and frost of the flower is extreme and the effect is equivalent to this.


“Help my weed looks weird!” – The 5 most common problems while growing cannabis

Since Nebula has a VERY EXTENSIVE guide on every possible problem your plant could potentially have I will just give my two cents on how to fix about 90% of the problems that can occur when you are new to the subject.

1. Discoloration of the leafs. 

This problem makes most first time growers loose their shit very fast. When you never had to take care of any plant at home it seems weird that there is something dying on a plant.

Main reasons leafs are dying:

  • Leafs on the lower part on the plant die first. This is normal and occurs nearly everytime. Do not worry and move on. If you do not lollypop or defoliate it can happen that about 1/5 of lower growth will get dry in the course of the grow. The leafs are just light deprivated and the plant rather uses nutrition on leafs that get hit by more light.
  • Leafs turn yellow at the end of the life cycle. This is very much dependent on your nutrient schedule and genetic. Have you flushed your plants? The plant will try to redistribute nutritions down to the roots. The leafs will turn yellow. Its harvest time, and you are pretty much simulating fall in your tent. Its normal. Some plants do not get yellow in the end. Thats also perfectly fine. Yellow leafs, after stopping nutrient supply is a common reaction.
Flowering cannabis plant
Chocolope really puts on a fall costume in the end. 
  • You are in the middle of a grow, and did everything according to the nutrient schedule as well as the soils instructions about nutrients? You might have a deficiency/toxicity going on. Read more in the next section…

2. pH value

This is actually very important knowledge. Soil is and inert medium. That means it is a living environment and can deal with out-of-order pH-values.
Since I am not a hydro dude, I will just say this: Get your pH straight. Buy some measuring stripes and look closely at the graphic below.

pH value uptake chart
Graphic from howtogrowmarijuana.com

A good example is the tap water where I live. It has a pH value of 7.5 to 8.2. To make it simple: The pH value is responsible for the availabilty of certain nutrients your plant needs. It is similar to humans: If your diet is too one-sided you will get problems! The pH value in an inert medium can be buffered to some degree, meaning that a slight off will be taken care of. 
My water will prevent most of the Copper, Zinc, Phosphorous and Iron to be left out in the feeding schedule and this will show in Leaf discoloration, reduced yield and growth and an overall unhealthy look.
Tip from the pro: Get a pH measurement device and dial that shit in. The optimal way would be the use of pH-up/down as a chemical addition to the feeding plan for every watering. You can also use lemon juice concentrate, especially when working with soil. 

The perfect pH-value when working with soil is between 6 and 7.

3. The right temperature

The origin of cannabis in nature is pretty sunny and warm. A cannabis plant grows best between 20°C and 30°C. The optimal values would be the area between 23°C and 27°C. Since a lot of homegrowers do not use any climate control their only hope is air circulation and decent ambient temperatures. The temperatures of plants in vegetative growth can be slightly higher, according to the seasons: vegetative growth happens in the summer, where the temps are usually a bit higher. A plant can also go out of this range: A higher than 1500 ppm supply of CO2 and a very bright light can help a plants thriving at temps as high as 35°C! But this should not be the case for newcomers.
My tip: Build a setup according to my guides and check out how it dials itself in. If its in range, you are good to go. Do not expect massive outcomes if your room is always over 32°C!
If your room happens to be under your roof, without air circulation thats connected to active heating and temps are constantly below 18°C you will most likely stun the plant and the growth will come to a full stop. This will be lethal and most likely the death of your plants. A funtioning thermometer will work wonders!

4. Nutrition

If you read a few month online about growing you will notice that nearly everyone uses nutrition to some degree. The plant needs food to survive. You want it to create a decent amount of harvestable material in the end. Compare it to tomatoes: A food deprivated tomato will stay small and might not taste good. It needs light and the right diet to thrive and grow right. Its the same with weed.

People tend to overnute their plants at first! They read that they should put 5-10 ml that gooey brown stuff per 10l in their water and think: “Wow, that can’t be enough!”

Two weeks after these people usually message me on instagram.
Deal with nutes according to the instruction. That is also important for your soil! Cannabis grade soil is oftentimes prenuted to some extend and still people put in all types of liquids, solids, fungi, worms and FUCKING MOUNTAIN DEW into their soil even when the plant is only 2 cm tall.

Read the instructions and deal according to it.

Its pretty much fool-proof. And less is more with nutes!

This plant is three week old and very small for that age. It has to fight various deficiencies in its hydroponic environment.

5. The Watering plan

This is another controversial topic. I just leave my way of watering here:
I take up to 1/2 of the pots volume in water and flood the pot the plant is in. I do it gently to prevent the water from just pouring out of the bottom of the pot. This builds up airy channels in the soil and water can not be taken up by the plants as effective as before. 

This will also create a runoff. When about 15% of the water volume are coming out of the pot you are doing it right, and the soil is saturated with water. Only moist soil will be rooted up!
After that procedure I wait between 2 and 7 days. Depending on the root system and the overall environment (Temperature and humidity) the water will get used up more or less fast. When i can put a fingertip into the soil and it feels very dry I repeat the process. This will oxygenate the soil and prevents the plant from “drowning”. I did that in the past four years and it worked very well for me.
Overwatering and underwatering can look very alike by the way!
If you overwater, the leafs will turn droopy but will still try to hold up at the base on the stem, while underwatered plants will just drop the leafs and crumples. Underwatering will be solved by just watering them. The effect will be visible in a few hours after that and the leafs will look healthy again.
Overwatering a plant is also not lethal: just leave the plant alone for a few days and do the finger-tip test. 

over/underwatered cannabis plants

If all that does not help you, scroll up and click on the first link in this post.

Germinating Seeds

Germination is the first step to start a run. If you start from seed I would count the moment you put the seed into moisture to activate it as Day One in the vegetative state (D1V) of the grow. This is important to know, to keep track of your grow. After you have chosen the right genetics for your operation and a working setup its go time!

How to germinate Seeds

It does not seem very important how you do it. Do it the way you are the most comfortable with. Success depends on the age, storage properties and quality of seeds.

The Pros way: Paper towel method

The paper towel method is a good way to keep an eye on your babies while having full control over the properties. The items I am using include:

  • Paper towels (kitchen paper, toilet paper, handkerchief…)
  • Seeds
  • pH-measurement device (cheap option or reliable stripes)
  • Water
  • Depending on you water: carbonized water or lemon concentrate to alter the pH value. Tap water is usually a bit basic. Change that!
  • The lid of an old jam glass as some kind of petri dish.
Items used for germination
Germination Kit: paper towel, some pH regulated water, a jam glass lid, pH meter

Unfold the paper, and place it into the lid. Sprinkle some water in there. place the seeds in the middle and fold back the paper towel. Thats it! Keep the petri dish in a dark and warm (about 25°C – 28°C) environment and wait. The lid is a great way to keep the paper towel moist. Do not wet it too much! The initial root needs some motivation to search for moisture and will grow better that way.

Advantages of the paper towel method

You have full control over the process and you can look at the seedling soaking up moisture and grow every day, and more important you can check seeds that don’t germinate and sort them out from the start. You are also able to use a lot of different grow media with this method. The seedling could be placed into a hydroponics setup aswell as soil-like media.

Disadvantages of the paper towel method

You need to interact more with the seed. Once its sprouted you need to place it into your grow medium and this could potentially be very risky. Im always using a pincette to do that. It is better to not have to interact with the plant at that stage. 
It is also possible that the small root hairs that grow out of the main root will get stuck in the paper towel fibers. If you remove the paper towel to hasty you could rip apart the whole root. So be careful!
You will also have a hard time distinguish strains, if you have only one lid available.

root with root hairs
Germinated seed with visible root hairs in a jiffy cup.

Jiffy pot method

This is also a great way to do it! Jiffy pots are small pellets that get soaked with pH regulated water. Once it reaches it maximum size you can just put in a seed and wait. Keep the pot moist at all times until the seed sproutes. The material of the pot is actually designed for root penetration. Once you see roots coming out of the sides you can put the seeds with the pot into a bigger container.

jiffy pots

Advantages of the jiffy pot method

You can actually distinguish different strains by putting name tags into the pots. You also dont have to interact with the seeds after putting them into the pot, that reduces the risk of killing them by transplanting. Its also possible to use the jiffy for different grow media. Hydro and soil alike. Do not use jiffys in high pressure aeriponic setups. 

Disadvantages of the jiffy pot method

If you are not sure that the seed is actually germinating you cannot look at that easy. That way you might wait for a seedling to sprout that is not even germinating. This could cause frustration. In high pressure aeroponic setup debris from the pot can fall into the water circulation, clogging your system. Use rockwool instead.

Method 3: Put the seed right away into its final container

Thats also possible. Considering the timeframe from activation to sprout to first green it can take up to 14 days until something is happening. Since you should NEVER EVER look for the seed in your medium this could potentially be a game of luck considering that a cannabis seed is inherently more valuable than a tomato seed if bought from a breeding company. You just keep the medium moist and wait, until you see it sprout. I would suggest you turn the lights on AFTER the seed shows itself. 

Advantages of method 3

No interaction with the seed reduces the risk of loosing it to poor handling. Less transplantation means less stress which is good for the plant.

Disadvantages of method 3

As stated before, this is potentially a game of luck: You never know if the seed just took its time to get sprouted. You might even end up with two plants in the same pot if you decide to use another seed in there. It is also more difficult to dial in the right amount of moisture to get everything done. Keep in mind that moist is better than wet in that case… 

Cheap Hydroponic start

IKEA offers a 4$ starter kit for seedlings. It works great if you add some air stones to keep the solution oxygenated. Rockwool and hydrostones are also available dirt cheap there. If you want to germinated in rockwool and still want to be able to change the environment of the plant, this could be your choice!

Germination Tips & Tricks

The Cookie Box

Place your seeds in an old cookie box, or something similar thats opaque and can be sealed. It keeps the moisture in there, and you do not need to remoisture it every other day.

Use excess heat

Your PC, TV or is creating a nice amount of heat. Place your seedlings on there to make it nice and warm for them. If you do not seal the seeds in a some kind of enclosure this kind of heat will dry out paper towels. This is why I am using the glass lids: You can create a pool of water in there that will take a lot longer to evaporate!

24 hours in water

This is done by alot of growers: Just submerge the seeds 24 hours in pH corrected water. The seeds will soak very effective in that time. After that you just use one of the methods above and make sure that the environment is more moist than wet.

Rougen up the surface

George Cervantes is one of the godfathers of growing weed. In one of his books he describes his method of preparation: Put the seeds in a match box and shuffle them a bit. The surface will be roughed up and can soak up the moisture better. I never did that tho, but George knows his shit obviously!


When is my seed ready to get potted?

Assuming you used a method, where you just watched the seed germinate you will notice that the initial root coming out of it. Since its possible to place it right away into a grow medium it really does not matter when you put it in. 

Half sprouted seedling
I would wait a bit longer for that root to come out …


This way you can maximize the probability of success.

Seeds that are ready to go
These are more than ready!

What is so important about the pH, can’t I just use tap water?!

I could and probably will write lenghty articles about the importance of pH values in growing weed. In short: Cannabis loves a slightly acidic root environment. This means 6.0 to 6.5 for soil and 5.5 to 6.0 for hydroponic setups.
This is a question of optimazation, and a pH meter plus some additives to regulate it are a meaningful and cheap resource of optimazation.
If you do not care pH lockouts of several important nutrient sources are the result. Spend the ten bucks for some pH-down and some pH test stripes and never care anymore.

I did everything you said, but I some seeds just don’t wanna sprout 🙁

Dont worry! There is not a 100% success rate on germination. This can have several reasons. Bigger seeds tend to be more sproutable than smaller ones. If you have problems sprouting seeds a good breeding company will replace your order with new ones. Just write them a nice email, instead of flaming their product in the reviews and you are fine.

I put my seeds into the towel yesterday and nothing happend!

Dude, relax! The first virtue to develop while growing your own weed is PATIENCE. You cannot imagine how often you will get tested on that. It can take up to seven days for a root to show from the seedling. And another seven days from planting the rooted seedling into a medium until you see the sprout! Give it some time and be rewarded later. ITS WORTH IT!

The Pro Grows: Chocolope by DNA Genetics

Why should you grow Chocolope

Chocolope is a direct descendent of OG Chocoloate Thai which is basically an Asian sativa landrace.

Chocolope cannabis in flower
Chocolope putting on the fall colors in pre harvest. She changed to red, golden colors. The buds have a baseball bat structure and she stretches like a real sativa lady

I got these seeds from key’s of choc thai back in the early 90’s we selected for the best traits and quick finishers. We made only a few seeds of this and Drawoh is the man thats keeping it alive by inbreeding it more.

DNA Genetics, Source

The other part is Cannalope Haze a crossing from Orginial Haze and a Sativa landrace from mexico. Overall the Chocolope has a nearly 100% Sativa background which she shows in her grow pattern!

Items and Tools that I used for that grow

TL;DR – Chocolope

  • Strain: DNA Genetics Chocolope feminized
  • From seed to weed: 143 days (veg 76 days, flower 67 days)
  • Wet harvest weight (wet trimmed): n.a.
  • Final dry yield: 70 gr (2.46 oz.)
  • Effect: High / Head / Euphoric / Hallucinogenic
  • Taste: Sweet / Earthy / Caramel

Grow it…
…if you have some vertical space to fill up. She is a stretcher.
…if you like haze.
…if you want to be able to be somewhat productive after a smoke.
…if you have the time to spread her out.

Don’t grow it…
…if you want small compact plants.
…if you are a militant kush lover.
…if you rather sit on a couch after consuming.

The Grow

Germination and failed start: Week 0 – 5

Chocolope Seedling in a hydroponic setup
Chocolope seedlings surrounded by hydrostones in an IKEA hydroponic setup. Source: homegrow-pro.com

This was my first test trying to implement a hydroponic (high pressure aeroponic) setup. The system is called Bifarm Aerokit and I failed this machine completely.
The setup was okay, and the Aerokit is running smooth. After 5 weeks in the aerokit the plant was still poorly developed and small. I think it was stunned due to wrong nutrition plans. It was a nice experience, but I wont come back all too fast doing hydro.

In short: The water chiller is running hot, heating up the grow space. Its also very loud. If you want to deal with two sources of heat (chiller and light) you will have to implement an AC unit aswell. That could cost more than the aeroponic setup can achieve in the end…

Chocolope in an aeroponic setup
Chocolope after 5(!) weeks in the aeroponic setup. After this i ditched the system and transplanted her alongside six other plants into BioBizz Allmix. 
Source: homegrow-pro.com

Vegetative Stage – Week 5 – 10

After transplanting the poor girl she started to thrive very fast. BioBizz soil is made for this! I gave her my way of low stress training along with alot of lollypopping. 

Chocoplope in vegetative stage in soil after transplantation
Chocolope getting the metal hook treatment. 
Source: homegrow-pro.com

After another four weeks of vegging she was ready to flower. I went exactly as the nutrient schedule says with the BioBizz starter kit. She was thriving til then. Chocolope is a very larky plant with long internodial distances. To keep her in check its helpful to cut away any 3rd generation side branches. If done right, she reacts very good to spreading and bending.

Chocolope after it got trained with LST
Final shape of the chocolope before she starts flowering. All budsites have roughly the same shape and size. She will thank you with uniform growth in the flowering stage. Prepare for a massive stretch! Source: homegrow-pro.com

Flowering Stage Week 10 – 19

Chocolope show her sativa descent in the flowering in full extend. She is a nasty stretcher and needs to be controlled. My phenotype built very dense and baseballbat-like colas that where stuffed with buds.

Grow conditions were far from optimal. The summer was very hot and dry, which also effect condiditons in tents, that are not fully climate controlled. Temperatures of 30°C and more were more standard than exception. But she dealt pretty decent with it.

Chocolope in flower
Chocolope in flower – she is a massive stretcher!

About 6 weeks into flowering I stopped the nutrient supply. She reacted by showing off her beuatiful fall colors.

Putting Chocolopes stretch into perspective: 
She is in corner at the back left more than double the height of the critical directly in front of her.

Bad grow conditions and harvest

In the end the plant the conditions went worse: Moderate spider mite infestation and very few cases of bud rot needed to be adressed and quite a number of buds got lost in the process. I also tried to use neem oil against the mites in the late flowering stage, wich i would not recommend to anyone. Just throw the buds away if you dont like it.

Pro Tip: Do not spray any pesticide or insecticide on your plants while flowering. Its better to get useful predators to deal with these pests. You want to consume the product in some way. And you can not really clean the surface – like tomato or a pickle.

Pro Tip: Try to keep your temperature at 25°C +-/3°C and the humidity low in flowering to prevent bud rot.

Spider mite damage on chocolope
Spider mite damage on the leafs. Several buds had to be thrown away because of pest damage and bud rot.

Harvest Chocolope is a breeze.  The phenotype has a very nice leaf to bud ratio and can be manicured with ease. 

Pro Tip if you have spider mites on your plants at the end of a grow cycle: Hang the colas upside down. The mites are always looking for the highest spots on the plant and will gather around the stalk or branch of the cola. You can just burn them away with a lighter. Do not forget to clean your grow and dry area very thoroughly. Mites are a bitch to deal with. Make sure, they stay dead.

Sugary trichome on a chocolope cola.
Pictures with flash enabled really bring out the trichome density on that strain. She is covered in sugar!

Consuming Chocolope

Chocolopes effect is a clear high. Get out to your favourite smokespot in the green and get going. The effect is pretty strong and caused a few visual and auditive hallucinations. Prepare to get a good bit of tunnel vision and subtle music you might hear in the sounds of nature around you. After a while it really clouds your mind and you will drift away. This is strain is nice if you are alone and want a bit of time with you and your mind.
It also does not effect you for the rest of the day. You will get clear very lean but after a bit of time.
The taste is very sweet and earthy. The typical haze smell is missing, which is unusal for a sativa dominant plant, making this strain more atypical. One could also reason this characteristic comes from the bad grow conditions. We will know, when I grow her again.

Setup for the Avid smoker – The 3×3 grow tent

Grow tent in full flower
You can do this, with a setup described in this section. Source: homegrow-pro.com

Everything you need to harvest  10 oz. of dry material every 3-4 months!
I will list the items that are absolute mandatory to grow first. There is a list with additional items, that I deem useful below. Get started on your first grow tent!

General Assumptions

  • Your grow medium of choice is soil.
  • You grow in a grow tent.
  • You start from seed.
  • You are a grow enthusiast who wants to make the most of a given space.
  • You do not have to run this hobby on a budget. (Options for that below)

List of items

grow tent3×3 Grow Tent1$90amazon
light*400W COB Light 1$600timbergrowlights
pots3 gal airpots4$50amazon
soil*60l specialized soil1$15 – $30(see below)
nutrition*Trypack1$15(see below)
ventilationClip Fans1-2$10-$20amazon
clima controlTemp./Hum. Monitor1$3amazon
on/off switchProgammable timer1$12amazon
  • Tents are great to keep control of every aspect. You can change temperatur, brightness, humidity and even simulate seasons in there! Its absolutely necessary to get your tent completely dark to your needs. If you have a closet or a room where you can manage to create pitch black darkness, you dont need a tent. The brand of the tent does not really matter. 
  • Light: Your articficial sun. Good growlights are hard to find in the LED jungle. Read more about lights below.
  • Pots: They come in different varieties. Plastic, fabric, with holes in it from 0.5 to 30 gal. I choose the airpots, because they let air move through the soil, and roots are pruned naturally at the outlets, preventing root rot or rootbound plants.
  • Soil: Do not buy common gardening soil. Cannabis roots need space to roam. Specialized cannabis soil has the right consistency and is often perfectly balanced with nutrition. You can also cook your own soil!
  • Nutrition: Personal opinion about nutrition – as long as its marketed for cannabis and does not kill your plants every brand seems legit. It is more like a personal decision what kind of nutes you use…
  • Ventilation: Moving air prevents bud rot and keeps the branches moving. That creates resistance and your plant will grow thicker and stringer. Keep the vents on 24/7.
  • Filter system: Your main exchange for air. If you have to grow stealthy or at home you do not want to have the smell leave the tent. Get one of these asap.
  • Clima Control: Really important to keep track of your values in there. You want to know the numbers. Once you know its over 34°C in your tent all the time, you know its time to do something about it. Same with humidity.
  • On/Off switch: Over the course of 100 days of a grow you dont want to hit the switches twice a day at the same time. Automate that.


The light

Yes, the light is the most expensive item in a grow operation. Yes, you can save money on light, but this is the best option for a grow room of that size. Its cool, quiet and runs damn bright. It has the most recent technology behind it and does not need extra cooling. But there are alternatives.

PRO TIP: You need at least 35W/ft² of high quality LED/COB light or at least 50W/ft² if you use CMH/HPS lights, if you want max out the tent potential! There are thousands of options. Just make sure its a grow light. Spectrum, PAR, PPFD values and color of light are also important properties. Read everything about the theory behind light here.

Alternative 1 – The Quantum Board

Horticulturelightinggroup.com has a very decent 320 Watt kit. It has alot of advantages like better light distributions or overall efficiency. I just did not link it as first option because it only has 320 Watts, and we wanted to get the most of our room with the given conditions. If you are able to build these lights yourself with a kit, buy these! The magic behind Quantum boards are LM56c or LM301b LED chips from Samsung. If you can find other distributors using these chips, you can go for it.

Grow tent with a quantum board
Quantum boards have an exceptional efficiency and overall light distribution!

Alternative 2 – Other LED Distributors

Its true, Timbergrowlights is just an option when in comes to LED lights. There are several chips out there that are awesome to grow weed with.
Timber makes use of Citizen CLU048, Cree CXB3590 and Vero29 COB LEDs. But other companies do it aswell!
Cobshop.net has a 3×3 kit including 4 COBs for $480, but they dont disclose how many Watts you get in the end. I assume its 200 W, so only half of my first option.

Alternative 3 – Low Budget only

I will list them here only because they work. But do not expect wonders. Im talking about the infamous blue/purple or pink lights you find on amazon.
NO, they almost NEVER deliver the amount of power they have in their names, NO you dont need just one, but at least 3 of these “300W” varieties you find online. Which one you take does not really matter, they are all ok. They only use the cheapest LED technology, including chips and drivers. If you spend $210 on three of them, you will be able to light up your tent properly. But remember to tune up the ventilation system, because three of these bad boys run pretty hot in a 3×3.

Blurple light tent
Blurple lights – They just won’t leave me alone! Low costs – low yields.

Alternative 4 – HPS lights

A 600 W HPS light will get you pretty far in a tent like this. And it costs only $130. This can reduce the inital cost significantly, but keep in mind that these light run HOT. And by that i mean shit-i-might-need-an-AC-in-my-tent HOT. The price is low, but running this shit can cost you! Save some money, ditch the AC and the pay only 2/3 to run a sweet LED light in there and pay less for your production.

Alternative 5 – Build your own COB or Quantum Board light

www.ledgardener.com, is the best source for that. There will be a guide here soon….

Soil and nutrition – Globalization and availability

If you live in Europe you have different soil companies than in the US. So while you can buy BioBizz in Europe pretty cheap, it is better to choose Fox Farm. 

The right soil is very important for your grow. Your roots want a pretty loosy, oxygenated environment. Many soil companies put peat (turf) in their soil which is very harmful to the environment. Check the ingredients, if you want to save the planet.

EU soil recommendations

US soil companies


Same with as soil. It seems like there is a new nutrition company out there every week. Even the breeder try to jump on the nute train and handing out their own nutrition along the seeds. (Royal Queen Seeds and Green House Seeds for example.)

I will also only recommend nutrition that have an organic base. I just do not believe in chemicals, but thats up for discussion.

EU nutrition recommendations

US nutrition recommendations

Useful additions

There are a lot more items making your tent easier. These are nice to have, but not 100% necessary. This list is not not yet completed.


  • Depending on your method of germination you will need papertowels or kitchen paper.
  • Since germination needs a dark, moist and warm environment, you might need a propagation box. I just put them in an old cookiebox on my PC.
  • Do not touch seeds! Use a tweezer.

Seedling and vegetative stage

  • Seedlings do not need flooded with water. Use a pump sprayer and be careful!
  • If you plan to train your plants, you need gardening wires or metal stakes. Or anything else you can come up with. You can also just use a cord and bind them down.
  • Use sharp scissors, knifes or even scalpels to cut leafs!
  • If you see pests like mites or thripes, treat them with bio degradable organic insecticide. Be careful with that!

Flowering stage

  • Some genetics produce fat buds. Too fat to hold them in place. Use plant yoyos or bamboo sticks and wire to hold them in place.
  • If you see any pests in the flowering stage do not spray the buds with insecticide. Use predatory bugs to fight them. This is your chance to have a personal ladybug army in your garden.
  • Jewelers loupes help you watching the trichomes and help to determine the harvest window.

Harvest, Drying and Curing

Grow Lights – Theory of Light

In this chapter you will learn about the different aspects of light in gardening. It clears up all the different keywords and hopefully all technical terms that occur when talking about light.

Definition of Light

“Light” is actually defined as a thin part of the electromagnetic spectrum. Exactly the one we can see with our human eyes. 

Light can be divided into parts called photons, which act in theory as light particles. According to physics you can treat light as a particle and a wave simultaneously. We will need both ways in this chapter!

Short wavelenghts means high frequency. Higher frequency correlates to higher energy per light particle. Long radio waves, which can expand to several meters in wavelength have a very low energy per photon.

Electromagnetic Spectrum with the visible part in the middle. From: Wikipedia

Defining a light source

If you want to learn about lightsources such as Light Emitting Diodes (LEDs), High-Pressure Sodium lamps (HPS), Compact Fluorescent lamp (CFL) or Ceramic Discharge Metal Halide (CMH) you will not only have to look at the specs each of these lamps have, you also have to look at the theory on which the light is created. Every single light source used for growing has its advantages and disadvantages.

All light sources used for growing work with a the same rough principle:

Turn electrical energy (input) into light (output)

The devil is in the details. As always. What I will describe now is awful lot to learn and difficult to have alook through. But its worth the reading, and after this you will be more able to decide wether a light is “good” or “bad” for your cause.

What light does a plant need?

Plants have two main sources of energy: The root environment (soil, water, aeroponics, nutrition…) and the light that shines on its leafs. The process in which the leafs turn light energy to “food” is called photosynthesis.

Not every light that a plant is exposed to, is usable to do photosynthesis. A human eye can basically see every color between 390 nm and 700 nm, but is blind for colors that have lower wavelengths (ultra-violet) or higher ones (infrared). Humans are most sensitive for the color green. As opposed to plants. Keep that in mind when you get to the unit section

Plants have a similar spectrum, but see actualy green light the least. Thats obvious, since leafs are commonly green, so they reflect the green parts of the spectrum. The three ingredients in a leaf that are responsible for the reaction are Chlorophyll-a and Chlorophyll-b as well as Carotenoids.

Bottom: Spectrum of photosynthesis rate –  There is a big dip in the middle.

Top: If you build the sum of the three top spectra, and take into account, that the different parts that are responsible for the photosynthesis are available in unequally you get the lower spectrum. Chlorophyll-a is obviously the main driver for the process.

If you look at the lower spectrum in the picture above you can get a sense of what kind light a plant likes to receive: two broad bands of light between 400 nm and 500 nm and between 650 nm and 700 nm. One is in a blueish region, whilst the other is rather red. 

The Relative Quantum Efficiency

The three molecules (molecule groups) Chlorophyll-a ,Chlorophyll-b and Carotenoids are not the only driving factor of photosynthesis. In of the most cited articels from K.J. McCree (1972) he measured how the plants react to light of different wavelengths. He found, that the area around the green light (550 nm) is actually well used by the plants. Not as good as blue or red light, but up to significant margin! So green light is not inherently bad for plant growths.

Mc Cree curve showing the photosynthetic efficiency of green leaf material. The experiment is from 1972, so it might be time to reevaluate. In this graphic we see the impact of  red and blue lights in growing, but you can also imagine that green light is also important.

Measuring light – A jungle of units

Now that we have the favourite colors of a plants light dinner, we need to figure out, how much they need! This is determined by the amount of light a source can emit. This amount can be described with various units of measurement. Some of them make sense for growing (PAR, PPFD), others don’t (lm, lux), and the rest is not normalized and/or very subjective in a way that it is depending on the experimental setup one uses to measure it.(also PAR/PPFD).

The following part will enlighten you about the different units of measurements scientist and light distributors characterize light.
Note: I tried to sort the units in order if importance, starting with the most important one.

PPF and PPFD – Photosynthetic Flux
Photosynthetic Photon Flux Density

Lets dive right into things. So photosynthesis is a quantum process. Just think about it this way: A leaf is plastered with billions of little molecule-machines trying to catch light particles in the exact right energy range. The more machines are hit per timeframe the better. So PPFD counts the amount of photons (µmol) that hit a certain area (m²) in our timeframe (s). This results in the unit of measurement:  [PPFD] = µmol/m²/s

A PPFD value of 900-1000 µmol/m²/s is needed to saturate a canopy area of plants if you use a warm white spectrum!  How to get an even canopy using LST!

PPF on the other hand only counts the Photons emitted by a light source, but does not take into account any absorption effects. So if a photon is emitted through a source and runs right into a the case of the light, its counted towards PPF but not PPFD. [PPF] = µmol/s

The counted Photons also have to be from a certain spectral area between 400 nm and 700 nm. Everything else is not counted!

Two different lights: Blue has a smaller wavelength and can transport more energy per photon than the longer red. Source: http://www.shorstmeyer.com/wxfaqs/Blue_Sky/bluesky4.html

Example 1: Lets say we have two lights emitting 100 photons a second on a normalized area. One is blue, one is red. The blue photons contain more energy. The PAR value would be higher for the blue light. The PPFD value would be actually dead even because both lights emit the same amount of photons in the active range.
So which light is “better”?
Answer: The red one for flowering, the blue one for vegetative growth. This is also the reason “common grow lights” give you both parts of the spectrum which results in a pink look of the lights. (blurple if you want…).

Cannabis plant under a grow light with a blue/purple spectrum
Cannabis plant under a grow light with a blue/purple spectrum. Source: homegrow-pro.com

Example 2: We add a green light to the show with an output wavelength of 555 nm monochromatic light. Its PAR values would be better than the red light, but worse than the blue ones. PPFD would be dead even again. Do we take the green one now?
Answer: No! A green light is not effective to grow cannabis. The plants will not be able to do photosynthesis with green light, as effective as with the use of fullspectrum systems, because they simply reflect alot of it.

Grower inspects his plants with a green headlight.. Source

Conclusion: When reading about PPFD values in the description of your light, always take a look at the spectrum as well. If the light “wastes” alot of intensity on green wavelength the number is not as useful anymore! If you have a high PPFD value it can mean less if it has mostly a green spectrum.
Its also interesting to look at the light distribution a light creates at certain distances to the source and wether the source created an even output! If there is a disproportion between PPF and PPFD its often times a lack of optical diffractors that distribute the light uneven to the plants. Take a look at a HPS lamp that creates light in a very narrow area inside its tube. This creates a very uneven distribution on the surface area: Buds on the edge of the light cone will develop more poorly.

PAR – Photosynthetically active radiation

This is easy to figure out: You imagine a perfect black surface and shine a light on it. The hypothetical surface (m²) absorbs the energy at a 100% effectivity which you can measure. Within a certain timeframe we can now measure the power (W) emitted by the light in [PAR] = W/m². The counted photons are again in the 400 nm to 700 nm range.

Here is a subtle difference to the PPFD value we learned about in the last section:

Example : Imagine two light sources. One monochromatic red and one monochromatic blue one. The red one has an output of 200 photons a second with 700 nm in wavelenghts, while the blue one puts out 100 photons with 400 nm. PAR does not care if the plant can use this light, it just takes the values because they are in the range where we observe PAR. So regarding PPFD we learned that the red one should be twice as good as the blue one. But on PAR level both are about even, because the blue light can carry more energy than the red one and PAR only cares about energy over time on a certain surface.

Conclusion: PAR can be at a high value, because it gets pushed through high intesity of blue parts in the spectrum (more blue wavelengths). Always check PAR, PPFD and the spectrum.

Light distribution under a metal-halide light: perpenticular to the source direction the light is most intensive. PAR values might look good, but whats measured at a surface level is also important! 
PPFD takes uneven distribution into account

W – Real Power Draw (Watt)

The Wattage of a lamp is a good ballpark number to start searching for a light source. Its actually the first value I look at, and from there you start to compare lights on the same level!

The power draw from the wall can directly calculated into money that appears on your power bill. So this is often the first thing you want to check. After this, you find out which light converts this money to the best possible PAR/PPFD/spectrum combination.

Many light suppliers tend to market their lamps with this value to its customers. 

Blue/purple lights from various distributors will name their lamps after “artificial HPS equivalent Watts” to trick the customer. You might think that a 600 W LED with the an awesome blue/purple spectrum is the deal of the day. Be aware that these companies hide the true power draw in the description at amazon or eBay. And they are good at it. Don’t get fooled.
If you think you can have 600 W of high quality LED plug-and-play light for 100$ you are WRONG.

Always check for the real power draw.

  • If you’re going for HPS/CMH/Lowball LED light: Calculate with at least 50 W/ft² for decent results.
  • If you are using High-Quality LED Lights (COBs or Quantumboards): Calculate with at least 35 W/ft² for decent results.
This Phlizon is marketed as a 600W LED Grow-light for mind-boggling $89.99. Its actually a 108W shit light, thats not even suitable to light up a 2×2 tent. ONLY BUY THESE LIGHTS IF YOU ARE ON A BUDGET! This scam is actually the “Amazons choice”…….

lm, lm/W – Lumen, Lumen per Watt

Now we’re really deep down the cave. But still: Companies try to catch you with values like this! 

Lumen is one of the least scientific units around, but still has some meaning for interior architects and astronomers. The unit is an abbreviation from the units candela (which literally refers to the output of a burning candle) and the so called luminosity function.

Quote:  “[…]
luminous flux is 
weighted according to a model (a “luminosity function“) of the human eye‘s sensitivity to various wavelengths. ” (Source)

So if you are following you might wanna ask yourself something. 
First remember: The human eye can best distinguish green wavelengths, because it is most sensitive around the 555 nm value. A plant is literally blind in this region.
WHY would you buy a light only because it has awesome lumen values?!

As always: check the spectrum! If the light is mostly green it will have awesome lm values. And perhaps, if its a modern LED, also great lm/W values. But it might not really suitable for growing.


How The Pro chooses a light

When it comes to the decision for the grow lights people always hassle. The market is flooded!

  1. Determine the size of your grow area and find out how many of the sweet Watts you want in there. The unit might not mean much, but you gotta start somewhere! Example: 3×3 tents have 9 ft² of space, so we need about 315 Watts of High Quality Growers Masterrrace LED Awesome Lights, or 450 Watts of Lowball LED / Good-old-fashioned HPS or CMH lights. Make sure your light has a PPFD value of 700-1000 at canopy level, has a full spectrum (warm white) and an efficiency of 120-200 lm/W (remember that you can use this number only for lights with similar spectra).
  2. How is your budget? Great LEDs are expensive, but worth the money. Pre build ones come for $1-$4/W in various forms. So youre looking potentially at $315 – $1260 just for the light. If you want to save money you can choose low-quality LEDs for like $250 that will reach 300 Watt if you buy 2-3 fixtures. Or you just go for a HPS setup for about $150 as a bundle with reflectors and balast. (I wont go into the details here)
  3. Lower your expectations! Great, you just want to take a look into growing and chose the entry level LEDs. Thats totally fine! You can grow awesome weed with these lamps! But if you ever feel you are missing out on something, come back and read about the real LEDs.
  4. Did you really get the HPS?! Thats also fine. They are working for decades and give awesome results. Come back if you think about buying an AC unit and have nightmares about your power bill…
  5. You cant decide between two or more lights? Compare PPFD/PAR/spectrum values at the same Wattage and find your favourite! A light should at least bring the PPFD up to 700 – 1000 in the sweet spot.
Spectrum of a Mars Hydro 300 W light normalized by maximum intensity. The spectrum is good if you just consider the PAR spectrum, but misses out heavily between the red and blue lines if you take the McCree curve into account as well.

LEDs recommended by The Pro

I’m not getting paid for it (yet) but here are some lights i will approve. I saw the results from growers and if you want high yield, dense buds and fast growing weed with low internodial distances buy from them. They also tend to run much cooler than HPS lights…

Timber Grow Lights (US)
Horticulture Lighting Group (US)
Cob Shop (US)
Greenception (EU)
San Light LED (EU)
Rapid LED (US)

Build your own!

Don’t try to buy a good grow light on amazon.com

Low Stress Training – Bending your way to bushy plants and high yields

If let untouched, a cannabis plant usually has some kind of christmas tree shape. This is okay for a plant in nature. The sun will reach every part of the plant equally over the course of the day.

This condition is different in a tent. The plant will not get hit by parallel light, but rather by point light from a low distance. (In the case of HPS or CMH lights. Even the common LED lights are pretty limited in regards of their light emitting cone.)

One important rule for light: Radiance – the amount of light a leaf receives is divided by 4 when the distance is multiplied by two ( R ~ 1/r²). This counts for every light out there.

On the other hand, light height is determined by the height of the plants main bud. The cannabis plant usually builds up one main bud which will grow a lot higher than the rest of the plant. To determine light height depending on a main bud will automatically decrease the amount of light the side buds can potentially get!

So the main goal will be the following: Have all buds to be at the same height, so every bud can receive an equal amount of light. If you then have an aerial light source (Quantum board or a good amount of COBs) you will have the perfect light distribution in your tent. In this chapter we deal with the canopy of the plants and Low Stress Training (LST).

What is Low Stress Training?

Stress is induced if a plant is exposed to an unnatural change in its environment. Most of these changes are unwanted and should be adressed accordingly, other stressfactors can be applied and will result in the predicted outcomes. LST is one of the latter.

The training aspect of the whole operation is a result of the change you induce: The plant will react to the stress and will need time and energy to do so. The most common forms of LST involve some kind of obstacle to grow around or to deal with.

The usual way to apply LST to a plant is to bent her to the side to encourage horizontal growth. This causes the plant to distribute more energy to the secondary tops and will result in a more uniform bud structure. You will lose the uniqueness of the main top, but the net yield should be higher in the end. This also brings us to the main reason of LST: You can actually bring your light lower! This is good for every bud and will result in an even more increased yield and better quality of the product. Buds develop differently depending on its place on a branch. Lower buds will develop less good and will take longer to be ripe.

cannabis flower pre harvest
A Critical plant that has been exposed to LST constantly. The buds are all of the same height and roughly the same size.

When do you expose the plant to training?

As soon as the plant has established a strong rootsystem you can start. But the best indicator is to count the nodes of a young plant.
The nodes are created one after another from the main stem. The top of the plant is the main node, and under this main the plant will create second and third nodes. Since these secondary nodes are developed after the mainstem, they will always stay behind the main top. The moment you see the little nodes form, you can start the training. You can also apply LST a few weeks into flowering. Just make sure the stems are still bendy and won’t just break. The flowering stretch is still considered vegetative growth and the plant will still be able to be trained. After this, you should stop and just watch the her thrive.

Plants as little as this can be exposed to LST. The first hook at the stem prevents the plant to grow completely tilted. The other hooks bend down the main stem, while the second and third nodes get exposed.

second to third rotation of cannabis training lst
LST can look messy at first: It can also be used to spread out a plant. Every side branch of this Francos Lemon Cheese, Green House Seeds, will be a new main top in the end. You can also observe where fan leafs got removed to expose the stems to more light and air.

The Pros Way of LST: Gardening Metal Hooks

The most common way involves gardening wire which gets attached to the stems. This is pretty clumsy and you can hurt your plant very bad if done wrong. The pro makes use of gardening metal hooks that can be ordered online for cheap. Look for a secondary node you want to expose, bend away the stem and everything above it, so it gets hit by direct light. If there is still a fan leaf casting a shadow over the secondary node, you want to remove this fan leaf in the next step. THATS ABOUT IT!

  • Let it be: Keep the hook in there for the rest of the grow or replace it with a hook you set up to bend the main stem over one more time. Removing the hooks before flowering or in flower will result in a plant that grows inwards. And this is exactly the opposite of what you want to achieve with LST.
  • Recovery time: Let the plant recover from LST before you do it again. LST is not inherently harmful in comparison to super cropping or topping / fimming, but still stressful. Usually a plant recovers in about three days from LST and can be bothered with it again after it.
  • Bend it, don’t break it: Don’t try this if the stem is already rigid. The older the stem, the less bendy it will be. Be careful! If you break the stem it is always bad and the plant needs much more recovery from a broken stem.
  • Don’t use force: I lost a number of plants to this already. Less is more here, dont push with full force. The plant won’t tell you when its enough. It will just break.
  • Don’t use sharp wires: The plant will cut itself resulting in a bad injury. It is not inherently lethal but in the worst case your plant will just grow around the injury and the wire and is exposed to infections. This could end bad!
  • Check the plants: The recovery time is pretty short. Watch your plants closely and you will figure out the best way to use LST for you very fast.

Timelapse of a plant that got exposed to LST. This animation recorded the 3 days of recovery after the hooks have been setup. You can also see, that fanleafs that pointed to the center of the plant got removed.

LST and Autoflowering Cannabis

There is a big discussion going on about training autoflowers. I tried several training methods myself on autoflowers. Since the recovery time from LST is so short, there is plenty of time to do this to your autoflowers. Autoflowers are not vastly different from non-auto plants. Autoflowers do not want to bothered with LST while she is busy building up the sweet buds. Start as early as you can, and keep a close look on your plant.

training of an autoflowering cannabis plant
Alien vs. Triangle Autoflower from Mephisto Genetics that got exposed to LST. Its pretty much possible to do this, but with limits! Start as early as you can, and look for the signs of flowering.