Had anyone successfully kept red eared slider turtles in their pond in the North Eastern part of the USA? We used to have one indoors and always wished we could put him outdoors. We gave him back to the pet store because he was a little to hard to take care of. Now, with our large pond that has straight sides with overhanging rocks, we were wondering about getting a few and keeping them in a pond. There's a few placed in the middle of the pond a turtle could get up to bask. The pond is 3+ feet deep so the turtle(s) could go down and hibernate. I know in the wild they live outside, but am concerned about buying them from a pet store that has been heated all year round. Should we buy them in the spring so they can acclimate?
I don't know how a red eared slider would do in the northeast, but I built my first pond (had it built, anyway) specifically because I had a RES that had outgrown a 75 gallon aquarium indoors and I needed a permanent home for her. We love her- she is very much a pet and is quite "social" with people that she knows. That being said, she eats or destroys nearly everything vegetative. Water lilies, water hyacinth, water lettuce, anacharis, elephant ears/taro of all kinds, sagittaria... it is difficult at best to keep plants in "her" pond as most of them end up as pieces floating in the skimmer. I have since built another pond for plants. She gets out of her pond and into the swimming pool. (I'm in Phoenix). Periodically she wanders around the garden and digs holes in the dirt- the point being that without a block wall she could disappear into the neighborhood.
In your situation, and because RES are an invasive species, I'd consider contacting a "turtle rescue" in your area and see if you can provide a habitat for native turtles that may have special needs (after being injured, for example) or something along those lines. Unfortunately many people aquire animals from pet stores that they are totally unprepared to care for, so with a little research you might be able to do some real good. Just my humble opinion :)
We have 8 RES in our outdoor pond in NW washington. They have been in there 12 years. A 3 foot deep pond is NOT deep enough. Raccoons & other predaturs will catch them. Our pond is 8 feet deep & has many logs for basking. They hibernate there very well. If one is digging holes it may be laying eggs.