Looking to build a tank to hold local catch. Such as walleye crappies bass northern pike maybe a catfish. They won't all live together this is more of an observation tank. I also will want some kind of floating shelf so I can house some local turtles such as leather back, painted, and snapping turtle. I also plan on some small mud puppy that will call it home. How big should I build this tank and also what should I use for filtration and oxygen I'm new to large tanks and don't know terms or how to set stuff up. I would also like to keep this as low priced as possible. Thanks for any help or ideas offered.

