I’ve had luck keeping painted turtles with almost any type of fish. I get them when their about an inch in size and keep them with large, fast, and healthy rosy red minnows. They rarely catch them, and I’ve had one live with a painted turtle for about a year. Soon they recognize that they cannot catch them and eventually stop trying. Since then, I kept a painted turtle with plecos, large cichlids, and other fish with little to no nipping. Just try not to keep them with slow fish with long fins like angel fish, or there might be some trouble ahead. But that’s just my past experience.