That's the exact same tank as I have lol must be made from the same company at the same time or something.
BTW, if it is the same, then that's a 220g, not a 200. Should be 7'x2'x25''
OMG waterline above the tank was genius!! Looks freakin awesome!!
A school of clown loaches would be very colorful and not pester your turtles.
Yes I like the black barred silver dollar idea. You could do a school of 6 or 7 in there and they would not bother the turtles. Use ordiary redhook silver dollars if you are unable in find the black barrs.