Grow marijuana hydroponically in an inert, sterile growing medium where all the nutrient requirement of the plant will be supplied by the nutrient solution. Nutrients that are typically required by marijuana will be nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sulfur (S). Besides these macro-elements, the micro elements are iron (Fe), chlorine (Cl), manganese (Mn), boron (B), zinc (Zn), copper (Cu) and molybdenum (Mo) which are required by plants in traces.
Advantages of growing marijuana hydroponically are:
- Higher yield
- Less space per plant
- Faster maturity cycle and therefore more crop annually
- Control over the growing environment
On the other side, some of the negative aspects can be:
- Higher set-up cost
- Technical knowledge required to run the hydroponics set-up
Growing marijuana hydroponically is becoming prevalent due to the Oregon ruling which states that hydroponic nutrients will now be formally evaluated and tabs will be kept on the growth, quality and yield of medical marijuana. It is important to start with good seeds while growing hydroponic marijuana; medical marijuana must be of the best quality possible. A hydroponics garden can be used to grow just about anything. But, one should remember that this requires daily maintenance and you have to arrange for caregivers if you are away for more than a day or two. Marijuana seedlings require about sixteen to eighteen hours of light daily. After they develop a root system and leaf growth commences, they enter the growth or vegetative phase. The need for light increases, and light sources must be active almost all day. This stage usually lasts a month or two.
At the flowering stage, marijuana plants produce the most amount of THC. Once the flowering phase sets off, the height of the plant tapers down as most of the plant energy is used in the flowering process itself. You can start flowering when the plants are a minimum of about 6 inches high and have at least 4 sets of leaves. This will take 2 weeks to a month of vegetative growth in most hydroponic gardens. When you want to start flowering, cut the light back to 12-13 hours a day. The flowering cycle lasts for 2-3 months in a hydroponic garden, depending on the type of seed. After flowering ends, harvested marijuana plants are left to be air-dried.
Make sure you have a good supply of electricity to run all your hydroponics grow room equipment. Your grow room should be a cool area, but keep the temperature above 60 degrees F. Most new growers find it terribly difficult to maintain proper temperatures in their grow rooms. A room which can be fitted with an exhaust fan might help maintain constant temperatures. An exhaust fan on the ceiling will keep the temperature down and you can always upgrade to a stronger fan if larger volumes of hot air need to be removed.
Lighting hydroponic equipments which are popularly used for growing marijuana are Metal Halides or High Pressure Sodium Bulbs. Metal halide is best for the vegetative growth of marijuana. While high pressure sodium is in the red end of the spectrum and is best for the flowering phase. It gives best results when used along with a 250W HPS/MH digital ballast, bulb and reflector combo.