I have decided to get an Oscar (although I dont know which kind yet) but I need to know a few things before i buy. 1: A friend of mine has a tank that she is willing to give me but she only knows the measurements in inches. they are 36,12,20. Anybody know how to calculate the gallons??..if this isnt big enough i will go with the LFS tank. 2: I was looking at baby Oscars in Walmart and they had a black and white mixed colouration...will they have this when they get to be full size, or will they grow out of it? I havent seen any pics of adult Oscars with this colouring so far... 3: Which would be better in an Oscar tank..sand or graval? I really like the look of sand but do oscars? Thanks for any help you can give.