I have a 25 watt on my 75....It was a major help in beating down the ich population in my tank...I believe it gave a couple of my fish a better shot at beating their ich along with good nutrition and better water quality.
Many people don't use them in reef because they're afraid of it frying plankton....which I'm sure it does to some extent...but I do'n't think it eliminates all the plankton in a system...not all the plankton will pass through it...and I know my corals are growing great, whether that's from just good light and other conditions or whether it means I've still got alot of plankton in there I dunno....so basically...my system is doing well...whether it could be doing better without uv I'm not sure...but it doesn't seem to be hurting it.
