GrowCaColacommentedweek 28 years ago
WIth HID lighting put your hand at the level you think the top of the plant should be. If your hand heats up to an uncomfortable level at all, then its too close. You want it to be as close to the plants as possible without burning them for maximum light density. Also, running a co2 bag, like an exhale co2 bag, will increase the stress your plant can take before they burn or otherwise start to mess up.
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