This is a random comment but the most recent thread on the T247 so I thought this was the best place to post. I thought it was worth passing along but not worth making a new thread.
I have a 36" (about 32" of usable length with the overflow) frag tank that I'm lighting with a single T247. This light has crazy hot spots right under the fixture, and I was curious if I could find a point to raise it enough that it spreads out more evenly. I found that the magic height was approximately 20" off the water. I had it about 14" off previously, and was able to increase the PAR in the corners of the tank by 20 (from 50 to 70 on 100% blues). after raising it up 6 more inches. Just throwing this out there for anyone else that might be interested in trying to have a single fixture cover more ground.