well i got some new questions and well this is my planted tank and has 3 big silver dollars, the lighting i have to choose from right now is a double overdriven 4' t-8 fixture, or a stock 2 bulb t-8, right now the stock fixture seems to keep the moss going good in there , but need to get my plant knowledge up to figure how to stock and which lighting i should use? since the silver dollars are hard on plants, thus far.