Well I have a 46 gallon tank. I have 3 small koi and a cupple other gold fish and one comet.

There is no direct sunlight on it or anything. Im going out to wal mart to get a PH test now in a few mins.

its weird though because when I set up my tank back in November, it was fine untill it was under a window to long and then it just got algae and more algae. then I moved it and set it up again and now its just cloudy. I did a partial water change the other day and it seems a little bit better, still cloudy but a little better.