I have a 9" RTC and I really want to move him into a bigger tank, but the only thing he can actually go right in to is the 600g pool/pond. It is all set up w. filters and everything (there's a couple large koi in it right now for the winter) Can he go into this right now or should I wait till he's 12" or so? I'm worried he will have issues getting his food in such a large area.