Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Goldfish and Rosy Red Minnows contain high levels of an enzyme, thiaminase, that destroys vitamin B-1.
If you want to feed your turtle live food, then raise your own, and rotate species of fish that you feed to him (her?). Feed the fish really well, and they will be a healthy way to feed your turtle. You can gut load the fish, too, so the turtle can get better nutrition via the food you have just fed the fish.
I do not know much about turtles, will they eat things like crickets, meal worms or flightless fruit flies? I think the wider rotation the better. But research to see if these or other critters are acceptable feed for your turtle.