Hi, this time I'll be growing some Critical from Royal Queen Seeds. I got a bunch of those seeds so why not use of them as a little showcase item. The aim of this grow is to demonstrate that you need only 100$ to grow cannabis. So before anything else, here's a parts list:

and some pictures of the cardboard box I'll be growing in:
The Critical is the one in the front/right. The 4 in the back are Baby Boom cultivars from a little experiment and on the left in the bags are some buds I'm trying to clone and reveg, we'll see how well that goes.
Strain: Royal Queen Seeds - Critical
From what I hear it's a pretty good Hybrid with a nice amount of Sativa in it. I'm looking forward to the smoke.
Light: For this grow I will be using a Mars Hydro 2 400 LED fixture, since I had one of those lying around. If you start from scratch I would suggest that you build your own COB LED light.
The materials you'd need for this would be:
Coming to a total of 30$ for the light. For guidance and details on custom LED lights feel free to go check out the
Do-It-Yourself LED Building section.
Substrate/Medium: I'm using 90% Coco and 10% Perlite on this. You can, to save money use only coco, I just wanted to increase the total porosity a bit. Coco bricks for Terrariums should cost you maybe 2$. Good substrate should have the following characteristics: the ability to absorb, store and release water, no fine/dusty particles, preferably inexpensive. This would be: coco fibers, lava, pumice, baked clay, expanded clay, zeolite, bark pieces, styrofoam pieces (no joke) and a few more that you can find yourself once you understand the principle. Some of these materials may not be available in your region. But there are always substitutes.
All mentioned substrates can be mixed at will and there is almost no difference. Too much is written about the "best" mix. There is no such thing as the "ideal substrate". There are, in fact, thousands of ideal substrates. I believe that it does not matter what you use and in what mix, as long as they are "modern substrates".
The modern substrate is water permeable (10+% Airspace), it stores water (40+% Water holding capacity), but the solid particles, form stable spaces, through which the water reliably runs off. It will always get rid of everything that is too much, no matter how much you pour. Exactly this drainage function is destroyed by the addition of soil or fine coco particles. Earth fills the spaces and the drainage effect no longer works. By the way, a drainage layer is no longer necessary, the entire substrate is a drainage layer. There is still too little talk about the fact that the roots always need a fresh oxygen supply. Only when they are constantly receiving oxygen, they remain functional. The roots that suffocate and die; This is reliably prevented by a modern substrate. The drainage of the substrate simultaneously fulfils the requirements for continuous air and water supply.
Since modern substrates contain no soil, they have little to no life of their own. They dry quickly and you often have to water several times a day when it’s hot and/or your plants are in flower. Therefore, I sometimes add coarse peat to the mix. This is the type of peat that is harvested in high-moors and is available in the natural coarse form, When using this you can also get away with less Humic/Fulvic acids in the fertilizer. Be sure not to use too fine particles of peat, even if it is described as "dust-free". If coarse peat is not available, small bark pieces or coarse coconut fibers can be used. These organic components should occupy 15-20% of the total volume. If instead of peat coco is used, Fulvic acid should be added when fertilizing, but more on that in a bit.
I use the same substrate for all plants. This can vary in the course of the year from the exact composition, because I again and again use old substrate and also mix several different substrate parts indiscriminately. I am not at all concerned with the exact composition, but only pay close attention to the fact that only modern substrates are used; Without soil.
Water: My base is tap water ~7pH, on average my plants get 10% of the grow container volume/day. So a plant in a 11L Pot gets 1.1L a day. With a modern substrate, everything you know about watering is obsolete. One can hardly pour too much, but one can underwater easily. Indoors I water almost daily once the plants are big enough. This is regardless of whether the plants seem too dry or not. In early veg when growing from seed I might water less or skip a day. If it is hot, I water twice in a day. Not large amounts mind you. Half a Liter twice a day has shown itself to be better than a Liter a day. Very small pots, 10 Liters or less, must be irrigated more than twice a day depending on the plant size. All plants are watered the same. The only deviation are seedlings less than a week old; Those get watered the same but fed at half strength. Individual irrigation is not required if all your plants are in modern substrate. It is also no longer a problem to travel and to bring a trustworthy person to do the pouring. Every half-hearted person learns this in five minutes. Everything must be thoroughly drenched. It also does not matter what type of water is used. Tap water is very suitable for all plants, even if it is hard water. I have one of the hardest waters in Europe in my garden (23 ° DH). Nevertheless, I use it for everything. You can also water with rain water. This is not that much better than tap water as many may think. On the contrary, you have to supplement it with lots calcium and magnesium. In tap water are many minerals, in rain water there is nothing. Except for sulphates in acid rain
This type of irrigation can also be called aggressive. The water must drain over the substrate’s surface and from the drain holes. The area is wet and it often takes hours until everything evaporates, which again creates a good microclimate for vegging. With modern substrates, overwatering is almost impossible. Many plants suffer or die because they sit in a modern substrate and are watered according to the old methods - they are clearly watered too little and almost die, looking sad and droopy, of thirst.
Feed: With modern substrate and aggressive watering, fertilization is no longer a secret. Almost every normal fertilizer is usable, whether organic or mineral (chemical). Fertilizer for cannabis must definitely contain nitrogen, a lot of nitrogen. Only plants with nitrogen can grow. In fact, you can only train cannabis, that grows well so you can always cut away something that has grown; Namely fanleaves occluding lower bud sites. This requires more fertilization than other plants. An ideal ballpark ratio of the final nutrient solution is 1:1:2.
I use the solid fertilizer, which is offered in granules in boxes. The solid kinds are the cheapest and I’ll give a few samples and comparisons for a KISS line at the end. For all my plants, I use the same fertilizer. Mix
In the past, much thought was given to which fertilizer was needed at what time of the grow. However, the plant knows best and takes what it needs. If aggressive fertilization and watering is applied, it is rapidly washed out and no salt can accumulate in the substrate. It is ok to fertilize with the same fertilizer in veg and flower as long as it covers “everything”.
How much? MUCH MORE THAN YOU THINK! Every day, for example, I give my plants 0.11g of nitrogen and potassium and ~0.25g kalium. Full strength fertilizer from day 7 above ground.
Now, of course, most of you think that what I am doing is too much and there must also be disadvantages. It is not too much, and everyone can get a picture in my garden at any time. Many recognized graduate gardeners and bonsai gardeners have already praised the health of my trees. So now I’m applying what I learned to this fun little plant. It’s also cheaper as I’ll demonstrate later.
Mineral, i.e. chemical fertilizers, are essentially salts. People are therefore often dissuaded from using them because salt can accumulate in the soil and thereby make it toxic. Too much salt in the substrate is almost impossible if you aggressively water every day. At each water pass, the excess salt is washed away. That is why you have to fertilize so much more!
I insist on aggressive watering parallel to aggressive fertilization and the use of modern substrates. Simply fertilizing aggressively without taking the other parts into account can be very dangerous.
You can make fertilizing a science and do everything meticulously according to regulations and with records and equipment and a lot of effort. Well, you can also make food a science. But most people still enjoy it without scientific tables and a variety of devices.
Now let's take a look at some KISS Fertilizer lines you could use and their price in comparison with colourful liquids in bottles.
Each of these combinations can grow you some good cannabis for ~50p/plant. Yes "food grade" (used in food production) fertilizer is that cheap. All the fancy bottled stuff is just not necessary.
Pots: The beginning pot is a 1L pot, it produces a nice and dense 10cm rootball through air pruning. When a root tip reaches the air, it dessicates and dies. The next step is increased side branching of the newly pruned root. This ramification is quite needed for the plant to optimally take up water and minerals.
Clones: The next stage of this grow demonstration will be to cut the plant up for clones, and depending on how many make it they are going to be grown to maturity in 6 or 11L Root pruning pots.
Climate: Everything in this shoebox is powered by a 10cm fan inside the main tent, that pulls about 50cf/m through the cardboard box and another 70 through another inlet in the big tent itself. I don't use blower fans in my setups.
For cheap and relatively easy DIY solutions on this check out the DIY Projects and Reviews section. The materials you'd need for a selfmade fan and carbon filter will cost you ~17$. Just run 12V, 120mm, high static pressure computer fans on the same charger that's powering your COB light's fan.
Let me know if I forgot to cover anything and feel free to tag-invite people.

and some pictures of the cardboard box I'll be growing in:



The Critical is the one in the front/right. The 4 in the back are Baby Boom cultivars from a little experiment and on the left in the bags are some buds I'm trying to clone and reveg, we'll see how well that goes.
Strain: Royal Queen Seeds - Critical
From what I hear it's a pretty good Hybrid with a nice amount of Sativa in it. I'm looking forward to the smoke.
Light: For this grow I will be using a Mars Hydro 2 400 LED fixture, since I had one of those lying around. If you start from scratch I would suggest that you build your own COB LED light.
The materials you'd need for this would be:
- 09$ COB: Citizen CLU-038-1206C4-403M2K1
- 18$ Driver: MeanWell APV-35-36
- 02$ Mains Cable: If you want to be fancy you can get one with a switch in it.
- 00$ Fan Driver: I just use old cellphone chargers, just go check THE drawer for 6-12v DC output ones.
- 01$ CPU Heatsink: You can get them from scrappers for a few cents, get a BIG one with copper heatpipes (if your fan fails it'll keep your cobs alive till you notice)
Coming to a total of 30$ for the light. For guidance and details on custom LED lights feel free to go check out the
Do-It-Yourself LED Building section.
Substrate/Medium: I'm using 90% Coco and 10% Perlite on this. You can, to save money use only coco, I just wanted to increase the total porosity a bit. Coco bricks for Terrariums should cost you maybe 2$. Good substrate should have the following characteristics: the ability to absorb, store and release water, no fine/dusty particles, preferably inexpensive. This would be: coco fibers, lava, pumice, baked clay, expanded clay, zeolite, bark pieces, styrofoam pieces (no joke) and a few more that you can find yourself once you understand the principle. Some of these materials may not be available in your region. But there are always substitutes.
All mentioned substrates can be mixed at will and there is almost no difference. Too much is written about the "best" mix. There is no such thing as the "ideal substrate". There are, in fact, thousands of ideal substrates. I believe that it does not matter what you use and in what mix, as long as they are "modern substrates".
The modern substrate is water permeable (10+% Airspace), it stores water (40+% Water holding capacity), but the solid particles, form stable spaces, through which the water reliably runs off. It will always get rid of everything that is too much, no matter how much you pour. Exactly this drainage function is destroyed by the addition of soil or fine coco particles. Earth fills the spaces and the drainage effect no longer works. By the way, a drainage layer is no longer necessary, the entire substrate is a drainage layer. There is still too little talk about the fact that the roots always need a fresh oxygen supply. Only when they are constantly receiving oxygen, they remain functional. The roots that suffocate and die; This is reliably prevented by a modern substrate. The drainage of the substrate simultaneously fulfils the requirements for continuous air and water supply.
Since modern substrates contain no soil, they have little to no life of their own. They dry quickly and you often have to water several times a day when it’s hot and/or your plants are in flower. Therefore, I sometimes add coarse peat to the mix. This is the type of peat that is harvested in high-moors and is available in the natural coarse form, When using this you can also get away with less Humic/Fulvic acids in the fertilizer. Be sure not to use too fine particles of peat, even if it is described as "dust-free". If coarse peat is not available, small bark pieces or coarse coconut fibers can be used. These organic components should occupy 15-20% of the total volume. If instead of peat coco is used, Fulvic acid should be added when fertilizing, but more on that in a bit.
I use the same substrate for all plants. This can vary in the course of the year from the exact composition, because I again and again use old substrate and also mix several different substrate parts indiscriminately. I am not at all concerned with the exact composition, but only pay close attention to the fact that only modern substrates are used; Without soil.
Water: My base is tap water ~7pH, on average my plants get 10% of the grow container volume/day. So a plant in a 11L Pot gets 1.1L a day. With a modern substrate, everything you know about watering is obsolete. One can hardly pour too much, but one can underwater easily. Indoors I water almost daily once the plants are big enough. This is regardless of whether the plants seem too dry or not. In early veg when growing from seed I might water less or skip a day. If it is hot, I water twice in a day. Not large amounts mind you. Half a Liter twice a day has shown itself to be better than a Liter a day. Very small pots, 10 Liters or less, must be irrigated more than twice a day depending on the plant size. All plants are watered the same. The only deviation are seedlings less than a week old; Those get watered the same but fed at half strength. Individual irrigation is not required if all your plants are in modern substrate. It is also no longer a problem to travel and to bring a trustworthy person to do the pouring. Every half-hearted person learns this in five minutes. Everything must be thoroughly drenched. It also does not matter what type of water is used. Tap water is very suitable for all plants, even if it is hard water. I have one of the hardest waters in Europe in my garden (23 ° DH). Nevertheless, I use it for everything. You can also water with rain water. This is not that much better than tap water as many may think. On the contrary, you have to supplement it with lots calcium and magnesium. In tap water are many minerals, in rain water there is nothing. Except for sulphates in acid rain

This type of irrigation can also be called aggressive. The water must drain over the substrate’s surface and from the drain holes. The area is wet and it often takes hours until everything evaporates, which again creates a good microclimate for vegging. With modern substrates, overwatering is almost impossible. Many plants suffer or die because they sit in a modern substrate and are watered according to the old methods - they are clearly watered too little and almost die, looking sad and droopy, of thirst.
Feed: With modern substrate and aggressive watering, fertilization is no longer a secret. Almost every normal fertilizer is usable, whether organic or mineral (chemical). Fertilizer for cannabis must definitely contain nitrogen, a lot of nitrogen. Only plants with nitrogen can grow. In fact, you can only train cannabis, that grows well so you can always cut away something that has grown; Namely fanleaves occluding lower bud sites. This requires more fertilization than other plants. An ideal ballpark ratio of the final nutrient solution is 1:1:2.
I use the solid fertilizer, which is offered in granules in boxes. The solid kinds are the cheapest and I’ll give a few samples and comparisons for a KISS line at the end. For all my plants, I use the same fertilizer. Mix

In the past, much thought was given to which fertilizer was needed at what time of the grow. However, the plant knows best and takes what it needs. If aggressive fertilization and watering is applied, it is rapidly washed out and no salt can accumulate in the substrate. It is ok to fertilize with the same fertilizer in veg and flower as long as it covers “everything”.
How much? MUCH MORE THAN YOU THINK! Every day, for example, I give my plants 0.11g of nitrogen and potassium and ~0.25g kalium. Full strength fertilizer from day 7 above ground.
Now, of course, most of you think that what I am doing is too much and there must also be disadvantages. It is not too much, and everyone can get a picture in my garden at any time. Many recognized graduate gardeners and bonsai gardeners have already praised the health of my trees. So now I’m applying what I learned to this fun little plant. It’s also cheaper as I’ll demonstrate later.
Mineral, i.e. chemical fertilizers, are essentially salts. People are therefore often dissuaded from using them because salt can accumulate in the soil and thereby make it toxic. Too much salt in the substrate is almost impossible if you aggressively water every day. At each water pass, the excess salt is washed away. That is why you have to fertilize so much more!
I insist on aggressive watering parallel to aggressive fertilization and the use of modern substrates. Simply fertilizing aggressively without taking the other parts into account can be very dangerous.
You can make fertilizing a science and do everything meticulously according to regulations and with records and equipment and a lot of effort. Well, you can also make food a science. But most people still enjoy it without scientific tables and a variety of devices.
Now let's take a look at some KISS Fertilizer lines you could use and their price in comparison with colourful liquids in bottles.

Each of these combinations can grow you some good cannabis for ~50p/plant. Yes "food grade" (used in food production) fertilizer is that cheap. All the fancy bottled stuff is just not necessary.
Pots: The beginning pot is a 1L pot, it produces a nice and dense 10cm rootball through air pruning. When a root tip reaches the air, it dessicates and dies. The next step is increased side branching of the newly pruned root. This ramification is quite needed for the plant to optimally take up water and minerals.

Clones: The next stage of this grow demonstration will be to cut the plant up for clones, and depending on how many make it they are going to be grown to maturity in 6 or 11L Root pruning pots.
Climate: Everything in this shoebox is powered by a 10cm fan inside the main tent, that pulls about 50cf/m through the cardboard box and another 70 through another inlet in the big tent itself. I don't use blower fans in my setups.
For cheap and relatively easy DIY solutions on this check out the DIY Projects and Reviews section. The materials you'd need for a selfmade fan and carbon filter will cost you ~17$. Just run 12V, 120mm, high static pressure computer fans on the same charger that's powering your COB light's fan.
Let me know if I forgot to cover anything and feel free to tag-invite people.