If you are worried about burning your plants, feel the leaves if they are hot you can move them farther from the lights or set a little muffin fan or two over the tops of the plants which will cool them and prevent sunburn. I grow with T5 HO lights which can give 5000fc of light. I set the shelves lower than I would if I was using T12's or T8's. This accommodates the lower light orchids. I set those that require higher light on overturned plastic shoe boxes which brings the plants closer to the lights. Good luck Pat