Went to walmart.... Pretty sure my 3 year old cuz could keep fish better than them. Anyways they have 5 Oscars in one 2 gallon tank. I was going to get two about (1.5 inches long) How long would they be ok in a 20 gallon tank. And I have read that if you rais two together that they would be ok together but I dont know. Im going to get a bigger tank (135) just taking a little time to get the money right now. But any advice from someone with oscar experience would be nice. thanks.