It being a tall tank is even worse. No oscar in that tank. And when the last poster mentioned getting a small one for the tank then upgrading, your upgrade will have to happen within a few months. If you've never raised oscars, they grow fast, you need to have raised them and see it first hand to appreciate how fast they do grow. My latest oscar has grown from 1.5 inches to almost 10 inches in 6 months. They need pristine water with large frequent water changes and a good diet to avoid HITH/HLLE. Get a 75 gallon for an oscar. They say 55 is the minimum but if you've never seen an adult oscar in a 55 you don't really know just how cramped it looks. I keep my oscar in 6 foot 125 gallon and he uses every inch of the tank.