Rusty! That could be it and makes sense.. I will keep on eye on that and see if that is the case. I never thought of that.. Thanks.

My hood is vented with a glass barrier on a light mover so it does not stay still above the plants for more than a few seconds. My therory is that this is why I can keep them as close as I do. I check them everyday during the lights on to make sure we have no burns and so far so good.

Thanks for the input.