AFRO-thunder;3842021; said:First of all: There is no fully aquatic turtle. Every turtle species needs to have a dry area to lay eggs or to dry off at least once in a while.
Second: Musk turtles will do well in a 265g tank if they are accustomed to the depth and if you provide rocks, logs or something elso to climb to the surface. I have seen stinkpots in Florida springs in 3m depth, no problem for them.
Third: Maybe you want to google for pink belly sidenecks (Emydura subglobosa). They are good swimmers, have a friendly character and look stunning. But don't forget on the land/egg laying area!
Would one of those turtle docks be enough? Essentially a screen that goes in the corner? Or do they need land as in soil and stuff? I realize if you are looking to breed, you need to go all out with soil, but if your not, is a turtle dock enough?