Maximum Yield USA 2015 November | Page 140

DOUBLE-ENDED LIGHTING HPS in the past. This is cost effective for your wallet, with less replacement purchases, and, more importantly for the environment, it means less globes thrown out. Regardless of the size or scale of your garden, correctly disposing of HID globes is essential. These globes contain lead, mercury and a range of other hazardous substances that are safe when the globe is sealed, but if it is smashed (in a garbage truck, for example), these toxic substances are released into the environment. Final Notes So now we know that using DE globes means you will require less fixtures, your plants will grow faster and yield more delicious fruits and veggies, plus your luminaires will last longer! It seems like an easy decision to upgrade, but there are a few tricks of the trade when using these light sources for the good of the plants and for your own health. When installing the globe, always be gentle and use gloves or paper towels. You do not want to leave any fingerprints or oily residues on the glass, as this can reduce light quality and potentially cause weak spots after prolonged use. Always follow the manufacturer’s recommendations for the ideal height above the plant canopy for different reflectors, especially “DE LAMPS GENERALLY HAVE A 10-30% INCREASE IN LIGHT INTENSITY AND PAR OUTPUT OVER TRADITIONAL SE BULBS.” with 1,000-W DE globes, as they can seriously damage plants if the luminaire is not far enough away from the crop and appropriate ventilation or light movers are not used. I recommend running 600- or 750-W DE globes in a taller tent or growroom if possible (more than 7 ft.) and to take advantage of the digital ballast dimming options with younger plants. One frequent concern we receive is that the DE globes cannot be vertically bare-hung or used in a tube-style reflector. This is easy to counter, as it’s been proven multiple times that horizontally mounted globes are much more efficient for horticultural reflectors. Growroom temperatures will be generally lower with 138 Maximum Yield USA  |  November 2015