Advanced Hydroponic Growing Tips

Simply put, hydroponic growing refers to the practice of cultivating plants in a medium other than soil. Hydroponic media is inert, sterile, and provides all the nutrients plants require through a water-based nutrient solution. Most plants are comprised of water, from 80 to 95%. The rest is carbon, hydrogen and oxygen. Therefore, the proportion of nutrients is the plant is very small. Because of this, the hydroponic process must be closely monitored to ensure optimal nutrient distribution.

A typical hydroponic growing solution consists of micro elements and macro elements. Micro elements include iron, chlorine, boron, zinc, manganese, molybdenum, and copper. Macro elements include nitrogen, phosphorus, calcium, magnesium, potassium, and sulfur. Because the growing solution is directly applied to the plant’s roots, the plant is saved the energy of establishing an extensive root system, so the plant has more energy to grow, and in less time.

For the rest of this article, we will focus on hydroponically growing marijuana. The most common hydroponic system used in cultivating marijuana is the Ebb and Flow method. The chief advantage of this method is its ease of use. In this method, the plants are placed in containers filled with a growing medium, and several plants are placed in a tray. Below the tray is a reservoir filled with nutrient solution. The solution is pumped to the top of the soil, and is allowed to seep through the growing medium, through a hole in the container, and is re-collected in the reservoir. Most growers attach a timer to the pump, to ensure accurate feeding and for convenience.

The Ebb and Flow method is the most popular method of hydroponically growing marijuana. Along with its simplicity and low cost, this method requires low maintenance, so the grower does not need to constantly check the plants. The Ebb and Flow method is so effective, high yields are virtually guaranteed, even for the novice grower. Other hydroponic methods include Screen of Green and Sea of Green. These methods are favored by growers with larger operations, because they are fast and produce larger yields. The Screen of Green method and Sea of Green method vary slightly in the equipment involved, so growers must select strains of marijuana which flower quickly, based on the chosen growing method. Fully equipped grow rooms are available for purchase, allowing growers to skip the time and effort of building a grow room from scratch. You might pay a little more for a grow room that’s ready to go, but growers who have purchased premade grow rooms report that the time saved was worth the extra cost.

The simplicity and control inherent in hydroponic growing can allow a grower’s creativity to emerge. Achieving optimal plant production can be controlled by various factors. One factor is light. When considering a grow light, look for units which produce a similar spectrum to natural sunlight. Grow lights also need to be very bright. In the early days of hydroponic growing, growers mostly utilized high intensity discharge lights, or HID’s. These HID’s came in two main varieties: metal halide and high pressure sodium. Metal halide lamps produce a light spectrum similar to normal household reading lamps, or fluorescent tubes. This “cool” spectrum of mostly blue and green light is ideal for use when the marijuana plants are in the growing stage of development. High pressure sodium lamps produce a warmer, red/orange light, ideally used during the flowering stage of the plant.

Marijuana plants grow best when the light is between 420 and 730 nanometers in wavelength. High intensity discharge lamps produce copious light, but a lot of the lamp’s energy is wasted in the form of heat. Therefore, when using HID lamps, a good ventilation system is necessary. HID’s also require ballast to operate. To obtain a 250 W MH/HPS digital ballast, a reflector and a bulb, growers will pay around $250.00.

A new innovation in grow lights has arrived in the form of Light Emitting Diode lamps, or LED’s. As LED’s have become more available, many growers have opted for these lamps, for several reasons. First, LED’s produce the ideal spectrum of light while using 82% less electricity than that of HID’s. An LED lamp rated at 185 watts can produce the same light spectrum and output of a HPS lamp rated at a thousand watts. LED’s can last between 50,000 and 60,000 hours of operation, and LED’s do not require ballast. It’s easy to see why LED’s make ideal growing lights.

Marijuana plants, like all plants, have an ideal photoperiod; that is, the period of time which the plant needs to be exposed to light, in order to achieve photosynthesis. Marijuana plants need at least 18 hours of light during the growth phase. With careful manipulation, growers can extend this growth phase to 24 hours. The growth phase is the primary phase in which the plants need light. The next phase, the flowering phase, requires much less light, usually only 12 hours of uninterrupted light. The plants will bud during this stage. Finally, the dark period delays bud development and stimulates leaf growth. If the plants need to be tended during the dark period, only minimal light should be used, such as pale moon light, and only for brief periods of less than five minutes.

Another important factor in hydroponically growing marijuana is temperature. Because marijuana is native to central and south Asia, ideal growing temperatures are within 80 and 90 degrees Fahrenheit. For this reason, LED’s are preferred because the grow room temperature can be much more easily controlled.

Fertilizer is another key factor to consider when growing marijuana, especially so with hydroponic growing. During the growth phase, a mixture of Peter’s 20/20/20 fertilizer to each gallon of water will be sufficient. During the flowering phase, Peter’s 12/34/16 African violet mixture can be used.

Carbon dioxide levels need to be elevated during the flowering stage, for optimal growing. Usual indoor rates of carbon dioxide hover around 300 parts per million (PPM). This level of carbon dioxide has little effect on growing. The ideal level of carbon dioxide is 700 ppm. At higher levels, the plants will turn yellow, burn, and die. Commercial carbon dioxide is obtained via burning natural gas, and stored in cylinders, available for purchase or lease from welding companies.

Precisely cutting the plants, known as pruning, also should be considered. To prune marijuana plants, use scissors to cut leaves which are over four inches in length. This will keep the leaves at about one inch in length, as the plant transitions from the growth stage to the flowering stage. Don’t prune too much; this will shorten the intermodal distance and slow the growth, perhaps even altering the gender of the marijuana plant. Pruning should be kept to a minimum during the flowering period.

Leaching is a technique used by many growers. Leaching involves adding concentrated salts to the nutrient mixture. The growing mediums are watered to excess, and given time to absorb the salts. Shortly after this, the excess water is siphoned off, leaving the concentrated salts in the growing medium.

The humidity in central and south Asia is very high, so marijuana grow rooms must have this same high humidity level. Leaching notwithstanding, marijuana performs best when the plant’s roots are not continually moist. Much of the water used in growing the marijuana plant is obtained not from the soil or growing medium, but from the ambient air. For this reason, most growers do not water their plants daily, unless room temperatures are inordinately high. With such high levels of humidity, fungi and algae are kept to a minimum by proper ventilation.