We guess many have heard about the wonders of the hydroponic world, its variety of systems, the high yields, the high-tech gadgets and of course the quality high associated with those kind of grows.
So hydroponic grows consist of having your plants in a soilless medium which is flooded by nutrient solutions now and then. Its systems usually consist of a pot or several pots, a reservoir, a grow medium, a pump and a complete set of nutrients for your plants. They work in non-biological soil or (soilless medium) where the roots of your plants are held on a separate level from the reservoir containing the water filled with nutrients which is consistently pumped upwards to the tray holding the plants and then coming down back to the reservoir. So before we go into the basics of hydroponics firstly we should take a look at some of the pros and cons of growing with an hydroponic system.
Greater yields and higher potency (when compared to indoor bio grows ).
Fewer pests due to the use of non-biological soil, normally there is no need of pesticides.
The chance to control your plants environment.
Choosing between the vast array of systems and setups that fit your needs better.
Higher energy consumption
Requires some knowledge, not suited for first-time growers who don’t have any kind of experience at growing.
Everything happens faster, this is naturally an advantage but can also backfire since all pests, deficiencies and other kinds of stress happen quicker.
Higher running and buying costs of the equipment.
Your plants lose some smell and taste when compared to a biological grow.
Choosing your Hydroponic System
Choosing and running your hydroponic system is very important due to the costs associated with these kind of systems, your kind of expertise on the matter of growing cannabis, knowing the existent systems, the size you will require and how hard they will be to run should be one of your main concerns so here are the available types of hydroponic systems:
NFT systems (nutrient film technique)
In a NFT system the plants are held in a tray directly above the water reservoir, a pump sends the nutrient solution to the tray while the water falls back to the reservoir on the other end, meanwhile an air pump continuously oxygenates the solution in the reservoir. The plants normally sit on a rockwool slab that is cut to fit the NFT tray’s length and width, some NFT’s use net pots (the plastic pots full of holes), they’re usually filled with clay peebles cause they can support the stems very well and don’t tend to escape through the net pots.
EBB & Flow (flood and drain)
The EBB & Flow system is easily recognized due to its depth, the grow medium is held directly over the reservoir which pumps the water at a fixed rate until the medium floods and the nutrients flow down along the roots into a drain tube back into the reservoir. These systems are usually flat so that the water reaches all plants. This setup requires less pumping than an NFT, sometimes the water is pumped only three times a day.
DWC systems (deep water culture)
The DWC system works by suspending the plants roots in net pots directly over a highly oxygenated nutrient solution inside a larger pot, these systems are very simple and highly effective being one of the highest yielding hydroponic systems, this system creates a massive root that will feed directly from the oxygenated nutrient solution. They are a nice choice for new growers in hydroponics as they are of easy assembly and easy to operate.
Drip Irrigation Systems
A drip irrigation system works pretty much like an ebb & flow system with the exception of distributing the nutrients much more slowly through drip lines that drop the nutrients to and from the reservoir throughout the whole container or to the individual pots containing the plants, most drip irrigation systems use separate containers from its plants to ensure that every single one of them gets the appropriate amount of nutrients.
The wick system is probably one of the most basic hydroponic systems because it relies on a simple wick (or multiple wicks) to absorb the nutrients from the reservoir, the setup is very simple and probably one of the best DIY hydroponics! It consists on a reservoir holding the nutrients that are being oxygenated through an air pump, and on top of the reservoir the plants are placed, the bottoms are drilled before you add the soilless medium and the wick is placed inside going through the cutted hole into the nutrient reservoir. With this system its slightly more difficult to control the feeding
This one is another very good DIY hydroponic system, it consists on having a nutrient solution being held above the plant container(s), the nutrients will then go down to the plants that must be in a sloped container so that the water runs down the container and fells on the other end into to a catching reservoir held under the plant container. When the higher pot of nutrients gets empty and the lower one full you just swap them! Some of these systems use pumps to feed nutrients back to the original reservoir.
Auto Pot and Manual Pot
This kind of pots are used for one plant only, in each pot, a pump delivers those nutrients into the bottom of the pot until they reach the roots or they are manually fed. In these kinds of systems the roots drink as much as they can until they’re exposed and then more nutrients are pumped into the pot. These kind of systems are good for growing bushy plants but they do require a lot of supervision to ensure they don’t stay dry for too long.
Now that we addressed fully-fledged hydroponic systems there is another one that although it’s not considered an hydroponic system per se but it’s an hydroponic growing medium and so it’s not a biological grow as well even though it’s treated like one ! This is probably the best system for newbies coming into hydroponics to get familiarized with the tricks and trades of hydroponics. That method would be the coco-coir growing! Instead of using regular bio soil you use this medium which has basically the same consistency as normal soil but since it’s not biological it should be treated as an hydroponic medium and thus the PH, EC and feeding should be the one of an hydroponic system and not the one of a biological one. But we’ll get into details about it later in the feeding section of this article.
Now since hydroponics systems are used indoor that means you will be the one responsible for providing your plants the ideal conditions that they need to grow into beautiful plants with potent buds. Attending to that, this basically means you have to play “god”. It is your job as a grower to recreate the environment that suits your strain better as if it were being grown in nature so you have provide it the oxygen and carbon dioxide, the PH, the electrical conductivity (EC) the temperature, the humidity, the wind, the light, the soil and the nutrients. These will be slightly different from strain to strain but there are several rules that apply to every plant.
Ventilating your grow room
Firstly we will talk about ventilating your grow room or grow box which in my opinion is one of the most important aspects in indoor growing. Having this well attended will help you regulate the moisture in the air, the oxygen, the carbon dioxide and if you have a proper climate to grow cannabis it’ll also regulate your temperature. For example, inside a grow box I like to have a minimum one complete air renovation per minute, which means if I have a grow box with a base of one square meter (3’x3’) that’s two meters tall (6ft) I’ll have to guarantee that my ventilators will be able to push and pull at least 120 cubic meters of air to and from the grow box. That means you’ll need one for the air intake and another for the air exhaustion, the intake should be placed lower cause fresh air is heavier, hence it is closer to the ground, and the other should be placed higher in order to expel the hot air out of the grow box. This will help you control the high temperatures generated by your lamp inside that tiny space, if the air outside is already hot then use cooltubes for your lamps so that they will not generate heat inside your grow box.
If you have a grow room then the same rule applies with exception to the air renovations which will only need to be from 12 to 15 per hour (one per 5 min. minimum). Be sure to use activated carbon filters in order to hide the smell and having unwanted attention drawn to your grow. You should use dehumidifiers to control the air moisture if needed as well as heaters. In order to recreate the wind use fans inside your grows, this will keep the plants and the air moving, avoiding the formation of hotspots and also strengthening your plants structure by keeping them in constant effort against the air flow generated by those.
The lighting is another important aspect since it is the one responsible for feeding your plants alongside the nutrients! As you probably should know those little pigments called chlorophyll are responsible for the photosynthesis, which will allow your plant to capture the light energy converting it into chemical energy that will be used to transform the nutrients captured by the roots into organic living tissue while releasing precious oxygen to the air. We will be addressing the lighting issue first.
So for the lighting you should use high intensity discharge lamps (HID) such as metal halides (MH) and high pressure sodium (HPS), light emitting diode lamps (LED) or compact florescent light (CFL), but we will only talk about the HID’s since those are the ones primarily used by growers all around the globe. Now you should understand that everything from the power of your lamp to the color range and wavelength as well as the luminosity will have different impacts on your plants. Firstly we need to understand that there is no better light source than the sun and so lamps won’t be as strong as the sun nor they will be able to recreate it as light source so we have to keep the following aspects in consideration. The power of your lamp, measured in watts, will have a direct impact on the luminosity, which is measured in lumens, which per se will affect the size of the area in which you are allowed to grow in order to achieve optimum results with your lamp in the following ratio:
250W HID – 2’x2’ area
400W HID – 3’x3’ area
600W HID – 3,5’ x 3,5’ area
1000W HID – 4’ x 4’ area
Now knowing this we still have to talk about the impact of the light color or correlated color temperature (CCT), measured in Kelvin, in your plants. You should have this in consideration when choosing a bulb or bulbs for a grow! A bulb that has a CCT of 3000K it’s considered a warm bulb, one that has 4000K a neutral bulb and one that has 6000K is a cool one. The color of these will not only be different as it will also promote different growth stages in the following measure:
From 5000K to 8000K it shows a deep blue light and will encourage excellent leaf and stem growth.
From 4000K to 5000K will show a light blue color and it will encourage a good leaf and stem growth.
A 4000K bulb will show a neutral white color and it will promote normal growth
From 3700K to 4000K the bulb will have a warm neutral color and it will promote a rapid growth.
From 3700K to 3000K the manifested color will be a warmer yellow that will encourage an active photosynthesis for all stages of growth.
And from 3000K to 1500K it will have a hot orange or red color that will promote flowering.
As for the feeding of the nutrients you should take the following aspect in consideration, the strain you’re growing (it might be a heavy feeder or low feeder), the kind of soil you’re using since it might have a low nutrient retaining rate or a high one and you should use this aspect in your favor depending on the kind of strain you’re using. Other thing we need to know about is what these nutrients are and how they’re divided. So we have three kinds of nutrients, macronutrients or primary nutrients composed by Nitrogen, Phosphorus and Potassium (NPK) which you will already find in the soil, the secondary supplements composed by Magnesium (Mg), Calcium (Ca) and Sulfur (S), which are also a part of the macronutrients these can also be found in the soil but not in sufficient amounts, and the micronutrients composed by iron (Fe), boron (B), chlorine (Cl), manganese (Mn), copper (Cu), zinc (Zn), cobalt (Co) and molybdenum (Mo).
Now these nutrients will have several different ratios and concentrations during the various stages of the plant and they’ll also vary according to the strain and medium you’re using. They should be fed at the following rate:
N, P, K are the base nutrients so these should be fed regularly according to your watering schedule.
Ca, Mg, S are the secondary supplements so they should be included once a week in your watering.
Fe, B, Cl, Mn, Cu, Zn, Co, Mo are the micronutrients and they should only be fed once every two weeks.
Apart from the nutrients there are other things you should have in consideration that will greatly increase the quality of your hydroponic grows and they are:
Fulvic and humic acids.
Bacteria for the root system.
B vitamins and other beneficial vitamins.
When preparing the solution you will feed your plants with you should keep an eye on both EC & PH of the solution! Why? Well basically because the PH will define your plants nutrient absorption ratio which means that at different levels of PH your plants will absorb better or worst certain nutrients but the reference value for hydroponics systems should vary between 5,7 and 6,2 being 5,8 the most used. You can also adjust your PH levels bringing them up or down if there is a specific nutrient you need the plant to absorb in order to correct a deficiency or something else, you should check a nutrient absorption hydroponic list in order to know the base values of PH for optimal absorption of each nutrient!
On the other hand the EC (electrical conductivity) will measure how much are you feeding your plants, these values will vary from 0.6 to 1.5 and they will change every week according to the strain you’re using. You should contact the seed bank ir order to know the best EC levels throughout the different grow phases of your plants. By measuring your run off water you should be able to adjust the EC levels into the ones desired by adding more nutrients or cutting off in case of excessive feeding. Using water that was filtered through a reverse osmosis system will bring your water EC levels to 0 which means you can fully supplement the water with nutrients until those reach the desired EC.
Garden maintenance and training
Now it is time for us to get to the final topic, garden maintenance and training, which involves a few different techniques you need to keep in mind in order for you to maximize your yield. Those techniques are LST(low stress training), HST’s (high stress training) and grow setups.
Now the LST consists of using the natural apical dominance of your cannabis plants in order to produce more colas and hence more buds. Apical dominance means your plant has a main branch which will normally be higher than the secondary branches and that will always try to grow closest to the light source as possible. By having a main branch the plant will distribute much more nutrients to feed this branch than to the secondary ones which generate less bud. This happens due to the fact that the other branches will be further away from the light and thus will not enjoy from being at the sweet spot when it comes to the distance between the branch and the light source (somewhere around 40cm, 30cm if you’re using a cooltube) where the plants enjoy 100% of the light produced by your bulb. This is done by bending the plant until the branches are practically at the same height and using a net to form a screen like in a Scrog setup and/or by tying down your branches. This will not also be useful in evening the heights of your branches but will also expose more growth nodes of your main branch to the air and light forming even larger buds. The advantage of this technique is that it can be used in all the plants without stressing them too much to the point where it can backfire and show some stunted growth. This technique will also help you control the height of your plants which can be very useful for example if you’re growing a pure sativa or sativa dominant strain inside a grow closet.
As for the HST’s they are divided Into pruning, topping, fimming, super cropping and thinning. These are techniques that’ll impose a lot more stress on your plants than LST so they should be made carefully and in a more controlled manner in order not stunt the growth of your plants.
Pruning consists of strategically removing parts of the plant by cutting them and hence increasing the number of node regions and also making those branches grow stronger if properly done. The prune cut should be made using clippers at 45 degree angle with a clean scissor or some plier. This will also remove the lowest branches which produce less bud and hence the plant will focus all its attention in the highest yielding branches, the ones closest to the light source.
As the name suggests topping consists of removing the top of the plant by cutting it leaving the first node at the top of your plant. This will mean that instead of one main cola you will now have two. This cut should be made horizontally with a pair of clean scissors or pliers.
Fimming or the FIM cut is basically a more advanced kind of topping. FIM stands for “fuck I missed” as this cut was accidentally discovered by someone who was topping its plant and missed the cut. This cut is made in semi-circular motion by grabbing the top of the plant which has the new leaves coming out and to cut about 80% of it. This cut will produce from 3 up to 8 new top colas.
The super cropping technique consists of pinching the branch between your forefinger and thumb carefully so that you can cause an internal rupture in the xylem and the phloem inside the branch without breaking the outer part of the branch. This will require some training as for you to know which side of the branch you should pinch without splitting the branch in two. This will cause the plant to reconstruct its vascular system but this time with two xylems and two phloem’s which will cause a swollen in the area where you broke it. This way your branches will grow stronger and thicker thus being able to produce more bud and supporting its weight. This technique should be carried out during the second or third week of vegetative growth, and it will stunt the plant’s growth, so you keep your schedule a few extra weeks of this phase to compensate for the stunt.
As you might know by now your plants will naturally compete for light with some ending up larger than others and covering the light that was supposed to reach the lower plants in your garden messing up the light productivity you’re supposed to enjoy. Now although this technique is more often used for outdoor growing some indoor grow setups such as SoG or SCroG will require you to do it in order to keep your canopy even and thus have the light distributed equally by all plants for maximum yield. Thinning consists of evening the height of your plants either by cutting them, bending them or removing the higher plants from your grow area in order to maintain the same height throughout all of your plants giving the light room to reach all of your plants equally.