Growing cannabis using hydroponics is no different than any other method of growing. It requires a lot of patience and the ability to take care of your plants. Research is important before starting with any form of growing cannabis, so you can avoid common mistakes that can destroy your cannabis garden.
Hydroponic growing systems are designed to deliver water and nutrients to the plant roots in a more controlled manner than conventional or soil methods. They are useful for supplying nutrients in situations where water quality is poor, such as with well water, or when using purified water for economic reasons.
The word "hydroponics" literally means the working of liquids. The practice of growing plants without soil, but with a water solution that delivers nutrients and minerals, is called hydroponic gardening. An advantage to this method is that the plants are not exposed to soil-borne diseases like Fusarium wilt, Pythium root rot, and Phytophthora root rot.
The most popular hydroponic method is deep water culture (DWC) which uses a large plastic tub or bottle. A few plants can fit into each container but they must be thinned out as they mature. A few holes are made in the bottom of the container and water is pumped in. The nutrient solution then trickles down to the base of each plant, to which an air stone is connected. The roots hang out of this stone and receive oxygen, while they absorb nutrients from the surrounding solution. A net pot or Rockwool cube holds the plant while it grows.
Things needed:
1.) a container like a bucket or a large bottle (with lid)
2.) plant pot with a small hole drilled in the bottom
3.) grow medium (like rock wool cubes)
4.) Net pot (you will need a few of these)
5.) submersible aquarium heater (with thermostat)
6.) air pump and air stone
7.) Submersible water pump - if not using an aquarium heater (must be able to control the flow of water into the container, with a dial or something similar)
8.) Hydroponic nutrient solution
9.) Waterproof tape and marker (marker is for writing date, time, and temp on your outside container (there are chips you can buy to do this))
10.) Optional: thermometer, pH tester, and other hydroponic nutrients)
How to do it:
1.) find a large container a 5-gal water jug or bucket. Drill a small hole in the bottom of this container (about 1/2" diameter).
2.) Use waterproof tape to seal the hole around your plant pot's opening, and then insert it into the hole. Tape the outside of the pot (around this area) to prevent leaking. This is where your new growing medium will go down into.
3.) Take your Rockwool cubes and throw them in your grow tray along with some nutrient solution (about half full, but you can adjust that later). Then take your net pots and fill them with water. Let them stand and soak up the water for a few minutes. This will allow them to expand on their own, making it easier to have your Rockwool cubes fit in nicely.
4.) After you've soaked your net pots, place them in the bottom of your hydroponic container (in between the plant pot and the growing medium).
5.) Fill up your large bucket/container with enough water so that it's about 1/2 - 2/3 full (do not put too much in or it will drain out). Attach the pump to the end of a hose and pressurize it. Connect one end of this hose to your pump and the other end to your container. Put it in a place where it will not be disturbed.
6.) Turn on your pump (if you have an aquarium heater, set the temperature here; attach the heater to the side of your container using heavy-duty tape or velcro straps). Also, make sure that your aerator and air stone are on now.
7.) Take a small amount of nutrient solution and pour it into a cup. Take some pH testing liquid that is provided with most nutrients, drop it into the cup, and swirl it around until mixed thoroughly.
8.) Take a test strip from your nutrient kit and place it in the cup along with the liquid. Wait about one minute for the strip to turn into a different color. If it is within the ranges specified in your nutrient kit, then you are ready to add nutrients to your reservoir. If not, take another strip out and test again in another minute or so. Add nutrients in small amounts until it is within range.
9.) To keep track of your time and temperature, mark your container with a waterproof marker every time you add nutrients (you can also do this when dosing nutrients). This will be helpful when growing multiple plants at once because some plants react differently than others with certain nutrients (like iron).
10.) Once you add nutrients, it is time to plant your seedlings. Place the seeds in the net pots and cover them with a light coating of nutrient solution (or use the same solution you've been using for your test strips). You do not need to do much more than that at this stage. You should see new growth within 2-3 days (if you have germinated your seeds properly), which is an indication that everything is going well and there are enough nutrients for them.
11.) Once you have seen new growth sprouting through, place your grow lamp over your container so that it shines on all sides. Make sure to account for temperature and lighting needs based on what stage of growth your plant is in at this point. At
What For Me, you can find more information about the optimal lighting requirements.
12.) Now it's time to add nutrients to your reservoir and monitor the color on your test strips. Once you have added all of your nutrients, place a test strip in your nutrient solution. It should be a dark green color if the pH is between 5.8 and 6.2 (the pH will be higher towards the end of the flowering stage). If it is too light or dark, you will need to adjust accordingly (usually by adding more of an additive that you have too little of). You may do this step as many times as needed until it reaches the desired color.
13.) Water your plants regularly as needed.
14.) Repeat steps 3-15 until flowering begins (or if you have been growing your plant from seed with these steps, it will be at this point).
And that's it! This method is great for those of you who are short on time and money. It is also great for smaller growth because it doesn't use a lot of electricity or materials as some other methods do.