I have mine about six inches above the tank. It's a tall twenty gallon tank, 20H I believe.This is exactly the thread I was hoping to find! Between this thread and TeleGraham's reviews on HumbleFish, this looks like it will be a good investment.
I ordered one of these to replace my little NiCrew 30w over my IM Nuvo 20 and I should have it by the weekend.
I wrote down a bunch of everyone's settings so I can play with them a little when I get it.
My only question then would be placement height. How high about the tank would be ideal for my 20g?