Growing Marijuana Hydroponically
Hydroponics can be a bit intimidating at first, however it has distinctive benefits over growing outdoors, and sometimes is the only possible method available. Plants grow faster with better yields. The theory is that if the plant has the nutrients readily available in the most easily utilized form, more energy can be directed towards growing and producing the desired product. The plants can be given almost continuous light for intensive growing. There is also no problem with soil conditions of climate problems. The largest benefit is, of course, it is the best solution for clandestine growing.
The drawbacks are the high cost of electricity and equipment. It is also not quite as simple as throwing some seeds into the soil and waiting, pipe in hand, for results.
You will need:
• A confined place to grow
• A nutrient delivery system
• Nutrient solution
• Seeds or seedlings
DWC (Deep Water Culture)
This is one of the cheapest and easiest hydro systems and is recommended for beginners. Basically, you need a light sealed container to hold the nutrients and a porous growth element suspended in it. The container has to be sealed against light to prohibit the growth of algae. You also need an air-stone suspended in the solution. This is plain and simple and produces fine results. The drawbacks are that it is not good for a quantity of plants and it is susceptible to algae and other problems associated with standing water.
This is similar to the DWC system in that the plant is grown in a porous medium suspended over a bucket. The nutrient solution is pumped over the medium, soaking the roots, on a regular basis. The runoff is collected and recycled. This system has the advantage that it can be used more efficiently if you are growing several plants and there is less of a problem with algae. It is more expensive to set up than DWC and there is machinery involved that can breakdown.
Ebb and Flow
This is one step up from the Top Feed system. It is better suited for even larger setups. The porous blocks are arranged inside of a water tight frame, which is filled and emptied. It is even more of an investment, though more efficient.
There are many more techniques and systems for hydroponic growing. The ones described above are the most basic. For more advanced growers, there is Nutrient Film/Flow technique (NFT), Aeroponics, Misting, and many others. It is a technique that is growing and expanding all the time.
The magic of hydroponics is that plants don’t necessarily need soil to grow. They do, however, need nutrients that are usually contained in the soil. Basically, any nutrients the plants need contain nitrogen, phosphorous, and potassium. There are secondary nutrients such as calcium, magnesium, sulfur, and the plants need different ratios and amounts at different times in its growth cycle. There also trace elements that are essential but only necessary in tiny amounts.
Nitrogen is necessary for the vegetative growth, building cells, proteins, and enzymes. It is also essential for making chlorophyll. Phosphorous helps your plant make sugars, oil, waxes, and terpenes. It is necessary for healthy roots and flowers and to build up the plants immune systems. Potassium is necessary for photosynthesis and flowers. Marijuana plants go through growth stages and it will be important to match the nutrient to the plants particular needs.
Nutrients can be purchased in liquid form, pre-mixed, or in powder form that needs to be mixed with water. As I said, hydroponics is a little more complicated than throwing seeds into some dirt and waiting. Overwhelming your plants will not improve the results and may damage the plants. You will need to do several tests on the nutrient solution. The most basic is a pH test. Your plants will like a pH of around 6.0. Though the pH should remain at a constant, the level of nutrients changes with the growth cycles. An electrical conductivity meter measures the concentration of minerals in the solution. You should also check for total dissolved solids. There are commercially available multi-function meters.
Prepping your walls
As stated, the most expensive thing about growing hydroponically will be the electricity for your lights. Prepping your walls can make more effective use of your wattage. Rather than have the light rays spread uselessly, it is best to position the plants near walls that have been treated to be as reflective as possible. This also allows for a more even distribution of the light, so that lower branches receive light also. Black or dark colored walls absorb the light. You want as much of your wattage as possible to get to your leaves. White paint is a cheap solution. Glossy paint is less efficient and it is recommended to use paint with fungicide. Titanium white paint is very reflective however it is prohibitively expensive. It is usually used only on reflectors.
Mylar is highly reflective and a good option. It comes in varying thicknesses, 2mm being preferable. 1mm tears easily, making cleaning difficult. It is 95% reflective but if it gets dirty, the reflectivity decreases. It should be noted that Mylar and Foylon, which will be discussed later, reflect radiant heat and will therefore require ventilation.
Foylon is a stronger fabric, similar to Mylar. Whereas Mylar is a thin sheet, Foylon is a spun polyester fabric reinforced with foil laminate. It is more expensive but it is a better option for growers who plan on long term use. Attaching it to the walls with Velcro is a good solution, as it allows for easy cleaning and maintenance.
Aluminum foil is a bad solution. It is only 55% reflective, tears easily, and cannot be cleaned. It is also dangerous, being electrically conductive and flammable.
It is best to use lights that can be height adjustable so they can be close to your plants and raised as the plants grow.
Average daylight is 5000-10,000 lumens per square foot. You want your growing area to get between 7,000-10,000 lumens per square foot and the absolute minimum is 3,000. To figure out how many lumens per square foot you’re working with, simply divide the total lumens as marked on your lights, by the total square feet.
CFL vs HID
There is much dispute over which light is preferable, CFL (Compact Fluorescent Lights) or HID (High Intensity Discharge). HID is generally considered more efficient and produces better results. HID costs more to purchase and run, uses more electricity, is more difficult to mount and hang, and will require venting. CID is a good option for large volume growers with serious rigs, looking for serious results. It is also recommended that the grower does his homework and check out the efficiency of many smaller bulbs versus fewer, stronger bulbs. Cool white CFL bulbs produce more blue-spectrum light, which is what plants use for photosynthesis.
Seeds are dormant until they germinate. Germination begins as a reaction to conditions conducive to growing. It begins in nature when a root begins to grow and push the seed to the surface. This usually happens in the presence of moisture and warmth. The seed coat opens, and the leaves that were present in dormant form, spread and begin to grow. It can be expensive to purchase marijuana seeds so proper germination is needed to protect your investment. Seeds can seem dry and brittle and still be quite viable, though green or white seeds will not.
Hydroponic growers generally use rockwool cubes for germinating their seeds since they are inorganic and can be put directly in their hydro setup. Since they are made of an inert material, it will not interact with the hydro solution. They are cheap, easy to use, and highly absorbent.
The drawbacks are that they aren’t organic and therefore bad for your health and the environment. It is recommended to use a safety mask, goggles, and gloves, when handling dry quantities since the dust is harmful. It is not biodegradable and disposal is a problem.
Rockwool also has a very high pH and must be washed and treated before it can be used. It has also been noted that since it is denser than soil, clone seedlings may have difficulty getting air to their roots.
A better alternative for small growers is to use paper towels or to begin germination by soaking the seeds in water. Seeds can drown so if they don’t germinate after a full day, remove them from the water. Or you can place them between sheets of wet paper towels. When peeling back the towels, be very careful not to harm the newly sprouted root. It has been recommended to use bottled water for germination, since tap water contains chlorine and other additives that may inhibit or harm germination.
One advantage indoor growing has over outdoor gardening is control over your growing conditions. Temperature and climate can be serious limiting factors, especially for those living in higher latitudes. Indoor growing means that you set the season. The ideal temperature for growing bud is 80-85 degrees Farenheit. 90 degrees is the absolute maximum, requiring ventilation. Higher temperatures reduce the risk of fungus but also lower the potency of your crop. Night time lows down to 60 degrees shouldn’t harm the plants but regular doses of lower temperatures will affect your crop. When the temperatures are around 40 degrees, you risk losing your plants. There have been good results reported with temperatures around 95 degrees with CO2 enrichment or 1500ppm, good ventilation to lower humidity, and intensive lighting. It is recommended to return to lower temperatures once flowering has begun in order not to adversely affect potency.