turtles and koi ponds

Question
Hey, I have a 4x6 240 gallon outdoor pond.  I have 6 coi fish, 2 which are 4-6 inches, 1 that is 4 in and 2 that are 3-5 in. I also have 4 sun perch ranging from 3-6 inches long.  I also have 1 channel catfish that is about 4 inches long.   The pond is right at 2 feet deep and doesn't freeze all the way in the winter.  I have 3 water plants along the rim of the pond and a few spots with Bermuda grass and other plants growing over into the pond.  I did some research and found that the turtle would eat the plants and algae, but haven't found sufficient proof that the turtle would eat the fish.  I have a fountain and a waterfall also.  I was wondering if I did adopt or purchased a Red-Eared Slider if it would eat the fish?  Thanks for reading my question and taking it into account.

Answer
We currently keep a rescued juvenile RES turtle with several goldfish. As long as the fish outpace the turtle for growth, then they should be ok. They don't seem to bother fish that are about as big or bigger than they are. The turtle leaves them alone, although he has eaten the snails we put in there. The turtle and goldfish compete side by side at feeding time. The fish have gotten more brazen and will bump the turtle, and he sometimes gives them a flip of the front leg to back them away. Our newly constructed outdoor turtle pen includes a small pond for this young RES and we plan to move fish in as well. I have seen RES co-residing with similarly sized Coi and Plecotomus without problems.

I think the turtles will leave them alone as long as no fish are ill and make a slow target, and they are being fed well. Beware that RES will eat up your plants time and time again though. It is a chore. They love anacharis, duckweed and many other things. They also need some invertebrate prey from time to time too, like worms and crickets. Ours also likes seaweed sheets and finely grated squash.

Good Luck

http://www.anapsid.org/reslider.html