You'll keep turtles separate from fish and coral, they'll eat them!!! I don't know about sea turtles but I have friends that keep turtles and their care levels seems easy to moderate. Just give them some space to swim around. Of course, care needs to be considered when it comes to the species of the turtle since different ones maybe easier or harder to take care of.
could red ear slider turtles survive in a saltwater tank?..
or is it only fresh water?