Red teared slider turtle food?

Hello everyone. I have 2 baby red eared slider turtles, and i was wondering what i should feed it besides turtle food. I was thinking if i bought those cheap 1$=10 goldfish fishes, chopped one into small pieces and fed that. Maybe i can buy those frozen shrimp and chopped those into small pieces and fed my turtles those? Any suggestions? And please list other food supplements as well. Thank you.