Hydroponic growing is a method of cultivation where plants are fed through nutrient rich water. Some forms of none nutritious mediums (hydroton, coco-coir, or rockwool) may be used to support the root system, though it can grow without any medium at all. Typically cannabis grown this way is much healthier and potent, as the exact ratio of nutrients are given at the exact times of growth they are needed. In addition the plants grow faster and larger than their soil counterparts. However, hydroponic systems require constant care and attention. This constant care can be off set with a good set of nutrients, and a few timers. Growing in this manner requires buying specific nutrients, so there is less chance of a mistake. Some example nutrients are Canna, Advanced Nutrients, Grotek, General Hydroponics and Botanicare; all come with feeding charts that tell the grower exactly how much fertilizer to add and when to add it. The only thing the grower will need to do is check the pH of the systems, most nutrients will buffer it to the right pH automatically. For this reason, along with general higher expenses related to hydroponics, cannabis grown this way is typically sold for two to three times the price of normal grown cannabis.
Common terms for cannabis grown this way are "hydro", "dro", "hydro weed", and "ponic weed". As a rule of thumb, expect any variation of the word "hydroponic" to be used as slang for weed grown hydroponically. This is also a very common bit of bullshit, "It's dro dude"
Starting a Plant
First one must find out if any seeds are duds with the process of Germination.
Once the roots on the Clone show they may be placed into the netcup.
Deep Water Culture (DWC)
Deep water culture (DWC) is where the roots of the plant are constantly submerged in aerated water. This can be as easy as a bucket with aquarium air stones at the bottom, to as complicated as 50 buckets all interconnected and aerated with a pressurized air tank. This water can be change weekly, but is more common to only changed twice (unless contamination occurs); Once during the switch from vegetative growth to flowering, and then again on the switch from flowering to flushing. The plant is held in place by the use of a net cup filled with non-nutritive substrate. The most widely used substrate is Hydroton but other items may be used. The idea is to get something that the roots can tangle up in, that will block light, and that can be sterilize. Some example usable items are plastic BBs, Legos, fish tank pebbles, lava rocks, etc. To aerate the water a grower will have to get some sort of air pump. For a personal sized grow a dual head aquarium air pump will do the job. Get the largest air stones so the bubbles will be spread over the largest area in the water. When starting a DWC tank the water should be kept at the bottom of the net cup. The bubbles from air stones will pop, saturating the substrate keeping the seedling alive. Once the plants root system is large enough for a majority of the roots to be submerged the grower may let the water level drop a few inches. Because of the simplicity of these systems they can be made very easily, and can be a great starting point, even those who haven't grown anything before.
Nutrient Film Technique (NFT)
Nutrient Film Technique (NFT) is a technique where the plants are grown in a tray that has a thin film of nutrient rich water pumped in. This film is made by spreading out the water being pumped into the tray into multiple tubes along the entire edge. Plants in this system are supported with Rockwool, Rockwool is not re-usable and will need to be disposed of after use. Because of this it's unpopular for large underground grow operations, less waste = less worry. The roots of the plant are protected from light and the top of the Rockwool should be as well (to combat algae). The thin film of water will absorb into the Rockwool and feed the plant till the roots grow through. Once the roots are at the bottom of the tray they will feed directly from the film of water. The advantage to this system is there is a lot less nutrients used compared to DWC, and Flood and drain saving money (so it can be spend it on Rockwool...).
Drip systems use a technique where the plants are grown in buckets filled with non-nutritious substrate (coconut coir, hydroton, vermiculite) and nutrient rich water is pumped in from above. The water will drain through the bucket and either back to the reservoir, or it can be drained to waste. The amount of time in between waterings is up to the substrate itself. Hydroton will need to be watered a lot more than coir or vermiculite since the later will absorb and retain the water. The grower may be able to get away with pumping once a day with an absorbent substrate, and once every few hours with a non-absorbent substrate. Drip systems are more forgiving than other hydro setups cause the substrate will act as protection just like soil does. With drip system if the pump fails, there will be a few hours (hydrotron) to a few days (coir) to fix it. Whereas if a pump fails with a NFT system the plants will likely wilt in a few hours.
Ebb and Flow (AKA Flood and Drain)
The principals of E&F (Ebb and Flow) are very similar to the Nutrient Film technique. Every few hours (usually twice a day) a water pump pumps nutrient solution from a lower tank to an upper growing platform. The level of the solution is regulated by an overflow tube in the upper tray, which returns to the lower reservoir. Once the pump shuts off, the nutrient solution drains back through the pump into the lower reservoir. E&F is simpler than some other hydroponic techniques because aeration occurs when the tray drains, and the system does not require an air pump. However, the drawbacks to E&F are that the pump and tubing clog easier because the filters have to work in both directions, and all of the plants are growing in the same tray, which can lead to diseases and pests spreading faster.
This is by far the easiest way of growing hydroponics. Literally it's a rope sticking out the bottom of a pot of vermiculite and perlite, that's being dipped in a reservoir of nutrient rich water. The water is absorbed up the rope, and into the vermiculite feeding the plant. It's yields wont compare to a DWC system, but it is set-up far easier since their is no moving parts or need for electricity. To make a wick system the grower uses a nylon rope as a cotton rope may rot in the solution causing problems later on. The systems is made of two bucket, one for the reservoir and one the grower has drilled holes in the bottom the size of the rope. A few rope lengths two times as long as the hight of the bucket are cut and strung with a third of the rope sticking out the bottom. The rope bucket is then filled with a pre-mixed half and half medium of perlite and vermiculite spacing out the ropes as the bucket is filled.
Aeroponics is method of growing where the roots are suspended in air and sprayed by oxygen rich atomized water infused with nutrients. The water pump must be kept running to keep the roots from drying out however its advisable to allow it some cool down time so the motor does not burn out. Half-hour on/half-hour off will work.
Low Pressure Aeroponics is where a nutrient enriched water-solution is sprayed onto a plants roots. Some argue that true aeroponics is only those that use a high-powered spraying system, but it is a better classification to call them low-pressure aeroponics, since no medium besides air and water is being used. EZ-Clone sprayer heads are the best for this type of system, and can be found online, or in most hydro stores.
High-Pressure Aeroponics is where a nutrient-rich water solution is misted or fogged onto the roots of a plant. This is called high-pressure aeroponics because a much-more powerful pump is needed than most people use in their Aeroponics systems. The pumps strength as well as the sprayers head must reduce the water droplet size down to 50 microns or less for your aeroponic system to be "true" or High-Pressure Aeroponics.
An Aero-Bubbler is a combination of Aeroponics and a Deep Water Culture, you'll have the standard misting heads being pumped in, but the root container is a reservoir that contains a bubble stone or bar as well, letting the plants drink water and air if there is a pump failure.
Aeroponics/NFT is a combination of Aeroponics and the Nutrient Film Technique, which typically consists of spraying, misting, or fogging a nutrient rich water-solution into the chamber where the roots are, as well as having a constant drain, back into an external reservoir. No medium is used, and the plant is typically only supported by a neoprene cuff, and a net pot, leaving the roots suspended freely in the air. The advantages of avoiding root-rot caused by DWC comes from keeping the roots only soaked, never totally flooded. The advantages of Aeroponics is that the water and nutrients are broken down into a much smaller droplet size, that the plant can more easily gulp down. Also, it eliminates any need for aerating the water, as every time a droplet of water splashes a wall, runs down the side, or bubbles back into the reservoir, it is getting more and more oxygenated. Keeping your pumps/misters/foggers on a 15on/15off schedule can save a lot of power and pump life in the long run.