I am running 2 LED lights-one 135 watt and one 90 watt. I keep the lights about 16 inches away from the plants. Everytime I put them in the tent with this light, the top foilage gets yellow. Soil is Sunshine mix #4, runoff at 6.4, and inteneral temps of around 77-79. I can move the plants to seperate cfl based tent, and not have these problems. So weird. If anybody has any advice, by all means, chime in.