Is the pond bare liner? What is there to keep the turtles in the pond? Does it get cold enough in AZ for the turtles to hibernate?
Mike

Okay, have you got a note pad handy? Their claws will not tear EPDM pond liner. I don't keep mine in with plants but I did have mosquito fish in with them and they never bothered them. You will need a way to keep them in and a sandy beach area for egg laying and sunning.

There are about 2 to 5 inch rounded smooth stones that cover the bottom of my pond, but by only one layer. the sides of my pond are bare liner. Winter nights get down to mid 30's to lower 30's on our coldest nights. I don't have a enclosure around my pond. My backyard is sort of small and have a brick fence enclosing yard. My pond is completely surrounded by plants. If they get out of the pond will they try to escape out of my yard? Thanks for the advice.

I've had turtles in my pond for several years. My turtles are Eastern Painted which is very similar to a Red-Eared Slider. I've never had any problems with the liner.
The turtles will eat plants like lilies. They never destroyed my lilies, but many of the leaves have bites missing. They will also occasionally eat fish that are less than two inches. I feed my turtles reptile pellets from the pet store and various fruits and vegetables. They love watermelon and cherries.
The turtles will leave your pond if they can and it is difficult to keep them in a pond since they are excellent climbers. I have my pond surrounded with plastic fencing supported by rocks. They will need an area to climb out of the water and bask in the sun.
I would suggest keeping the turtles in the aquarium during the winter and in the pond during the summer. Wild turtles dig into the mud at the bottom of a lake or pond to survive the winter. Your turtles will not be able to do this and may die if the water temperature gets too cold.