Right now, the lights are hanging about 18 inches above the water level and they are still raising the temp up from 79 to 84 degrees when left on all day. I was hoping to lower them down to about 14 inches. I will probably only run the halides 6 hours or so per day to help keep the heat down as well as run some fans.
I must say that I don't care much for the color of these DE bulbs. These are some very bright 10Ks, but I was told they'd burn more like 13K's. Well, they don't. They burn like 10Ks. But, with funds short and the need to restock, I'll be keeping them for the time being and will eventually get some true 14Ks. The actinics are having a tough time competing with the halides and not much is getting through. Of course, its hard to really tell with the mirky water and lack of corals in the tank to make sure.