So, I went to my uncle's yesterday and asked to see his Oscar fish (he's had several Oscars over the years in his room). I go up to what I believe is a 30 gallon tank, where an Oscar is just sitting in one corner. After a while, he started swimming along the back kind of frantically. The substrate is gravel, with decent sized rocks covering the gravel. A couple small decorations and a big one. The tank is filtered and heated. The oscar, upon closer inspection, had some scales missing (I'm assuming from trying to burrow through those rocks). He has an empty tank and stand that looks to be about 50 gallons in his garage that needs cleaned out. Here's what I texted him yesterday: "Your Oscar is cute. He looked like he might be missing some scales, though. Oscars burrow so he may have scraped them off on the rocks or gravel (I did research on Oscars a while back bc I wanted one). He may appreciate a sand substrate instead of gravel and rocks (play sand or pool sand works and is cheaper than aquarium sand). Also, the minimum tank size for Oscars is 55 gallons. I think yours would appreciate being moved to the tank in your garage. It looks like a 50 gallon, but itll work as a permanent home for yours. I wouldn't mind coming out and helping clean out that bigger tank. Simple decor would work for him. Since he burrows, he would upset a complicated aquascape. Just a sand substrate and some driftwood (one large piece laid down would work). I also have a large fake plant that you could have that is connected to a weight so even if he does move it around it's easy to just drop back where you want it. He would really appreciate a bigger tank, and may liven up a little bit. I don't know how much he'll grow, though, as he may be stunted (not grow full-size) from being in the smaller tank." I also took some bad pictures because the lighting wasn't the best. It was a very cute oscar.