Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible

self-cleaning (or easy to clean) and easy, safe bulb replacement. When UV light encounters moisture in the air, nitric acid is produced as a by-product. This white, powdery nitric acid collects around the lamps at connection points. This is an unpleasant, very corrosive acid that will severely burn skin and eyes. Verify that the ozone generator has proper safety features built in, such as a switch that turns off the lamp for maintenance, making it impossible to look at the retina-searing UV rays. Legal exposure for humans is about 0.1 ppm for a maximum of 8 hours. Most grow room ozone generators produce about 0.05 ppm at timed intervals. See (page 348) for plant symptoms of ozone overdose.
    UV light is very dangerous. In a flash, intense UV light can burn your skin and the retinas in your eyes beyond repair. Never, under any circumstances, look at the UV lamp in an ozone generator. Sneaking a peek at a UV lamp in an ozone generator has cost more than one aspiring grower their eyesight! Ozone is also capable of burning your lungs. At low levels, there is no damage, but at higher levels, danger is imminent. Never, never use too much!
    The Air Tiger™, manufactured by Rambridge, www.rambridge.com , is an excellent value for growers. It is one of the safest available and easy to maintain. A deadman’s switch makes direct eye contact with the 10-inch-long UV light tube impossible. Highly corrosive ozone stays away from interior wiring, and little moisture can penetrate the outer shell to combine with O 3 to form powdery nitric acid.
    Ozone generators are rated by the number of cubic feet (m 3 ) they are able to treat. (To figure cubic feet or meters, multiply the length × width × height of the room). Some growers set up the ozone generator in the grow room and let it treat all the air in the room. They add a timer so the ozone generator intermittently disperses ozone into the room to maintain a relatively constant level. This practice can diminish the fragrance of the bud. Smart growers set up an ozone generator in a spare closet or build an ozone exchange chamber and route fragrant grow room air through the closet for ozone treatment before being evacuated outdoors. Other growers set up the ozone generator in ventilation ductwork to treat air before it exits. Once generated, ozone has a life of about 30 minutes. It takes a minute or two for the O 3 molecules to combine with oxygen to neutralize odors.

The Air Tiger is a very popular ozone generator that is designed to fit inside ductwork

Mixing ozone-treated air for a minute or more allows O 3 to shed a molecule and become O 2 .
Ozone Damage
    For best results, keep the ozone generator in another room or isolated from the growing plants. Ozone causes chlorotic spots on leaves. The mottled spots that appear at first to be a Mg deficiency, increase in size and turn dark in the process. Most often, the symptoms arefound on foliage near the generator. Leaves wither and drop, and overall plant growth slows to a crawl.

A vent-fan duct hooks to each tube, and the air-cleansing agent is imparted before air is evacuated.

Ozone generators are located inside ducting. Grow room air mixes with ozone in ducting and big metal box. Air smells fresh and clean once treated properly with ozone.
Activated Carbon Filters
    Activated charcoal filters are fantastic, and they work! The charcoal is “activated” with oxygen, which opens millions of pores in the carbon. The activated charcoal absorbs odor molecules and other pollutants in the air. The mechanics are simple, and there are three important things to remember when using a charcoal filter. First, keep room humidity below 55 percent. At about 65 to 70 percent relative humidity, the charcoal absorbs moisture and clogs. At 80 percent humidity, it stops removing odors. Second, air must move slowly through charcoal filters to extract odors. The fan on professional units lets just enough air through the filter so the odors have enough (dwell) time to be absorbed by the carbon filter. Third, use a pre-filter. The pre-filter catches most of the dust and airborne pollutants before they foul the carbon filter. Change the pre-filter regularly–every 60 days, or more often if the room is dusty. Carbon lasts about a year. Many growers prefer activated carbon made from coco. Do not use activated carbon that is “crushed,” because it is less efficient than charcoal pellets.
    Install an intake screen that filters out large particles of