I have 2 juvenile RES in a tank with some feeder fish. I bought 16 small fish about 3 weeks ago. There are still 10 of them left. How long does it take for them to eat them? I bought 10 of them 3 days before I got these and those fish were gone in 10 hours. My 2 RES turtles are 4" long. I see them hunt the fish every once in a while, but they never eat them. Just curious as to why they aren't eating them.