Well right now I have a choice of using either a established 10 gallon (freshwater) or a 16 gallon tank that my friend used for lizards. I was originally going to use the 10 gallon, but would it be smarter to use the 16 gallon? the 16 gallons dimensions are 24x12 (didnt get the height) as opposed to the 10 gallons 20x10 (again no height). I had found a 20 inch light for the 10 gallon, do you think that it would be sutable for this tank or do I need one that spans the entire top. The 16 is pretty dirty but I plan to clean it with some water and ammonia from my fishless cycling.