You need a minimum of 75 gallons or anything with the equivalent foot print 48" X 18"
as a MINIMUM. I have 4 and think they are just great. If you have time to pay attention to them and keep the water clean, you couldn't ask for a more active fish. They will interact with their keeper and always beg to be fed even if they just ate 2 minutes ago.
Don't cheap-out on the food as you will have nothing but health issues. They can easily develop bloat not only from para sites but also from foods poor in nutrients to overfeeding among other reasons.
Stay away from live foods unless you have raised it yourself and can attest to it being free of diseases. Using live food from a store is a good way to introduce illness and disease.
They are as close to a dog as you can find in the fish world. As with many other fish, they do recognize their owns and it is common to refuse to eat from anyone other than the owner. They are cantankerous, ornery, moody and stubborn and all at the same time if they wish, LOL.
Plants and decor are fair game to be used as toys or to re-decorate their tank
as they see fit. They will often rearrange substrate, plants and decor several times over. If it ain't nailed down, it's gonna get moved.
For more pictures of Oscars from members click here.