I've got 2 heads, my first. Not quit sure where to best place them. For now they're on a small piece of LR on the sand bed. Seem to be doing fine. But I've also had them up high on the LR and did fine there as well. Is one or the other better?
I run T5s in my tank and I have kept them for years everywhere from the top to the bottom and they do just fine. I do think that they grew a little faster when they were about half way up though for me. My tank was 24 inches high and the lights were about 6 inches above that.
I just moved mine to my tank with pc lights because in my main tank like stated above they were bright but not growing at all. I am going to let them grow on the bottom across some rubble instead of living on their little rock to see if it helps them spread.
I had some orange and blues that spread from single polyps to 20-30 polyps and I kept them from middle down under 5 T5s in a 24inch and now a 30 inch tank. In my setup I think they grew best in the middle but it depends how much light you have on your tank I would think.