Hi, my family and I are working on a koi pond in our backyard. I would eventually like to put a turtle in there (if possible). We aren't using a molded plastic piece, we dug out these two gardens that we aren't using anymore in the backyard. The pond ranges from 8 inches to 23 inches deep, and its about a 6x10 space. The main reason we are building this is to put bigger koi in it (we have a small tub right now with about 5 inch koi, and a frog), we haven't totally decided what size koi, but we are going to some pond places around here and just researching them.
I was reading online that a turtle needs to be able to come up on shore and have dirt under it's feet, is this true? Looking at some other people's enclosures, it doesn't look like it needs this. I know RES's need basking spots (floating pieces, etc) and half of this pond is in direct sunlight, so that part isn't a problem, and there will be plenty of plants in the enclosure.
I know alot about reptiles in general, I've had bearded dragons, leopard geckos, and anoles, but never a turtle.
I'm not even sure if a Red eared slider is the best turtle for this pond, but any suggestions would be greatly appreciated.
Thanks.

