Hell no you should never put any turtle ally or snap in tanks to gether or with other turltes. That is unless you are feeding your ally/snaps, turtles. the will harm each other and it would be a big mess. Dont even think about it. If you wanted to get other turltes like get Res and put them with maps that find but ally and snaps should be kept in their own places.
:Is it possible to keep snapping turtles together with other species of turtles when there getting bigger? Can you keep adult alligator snapper together with adult common snappers. I presume you can keep them together untill a certain size?