How often do you feed your baby red eared turtle?

I have two red-eared sliders, and a yellow-bellied slider. I feed them once a day, everyday. I feed them all at the same time--in the morning. It is usually between 6-7am during the school year, or 9-12am over summer break. I use turtle food bought from Pet Smart. In it is mini sticks (scientist made stuff,) mini shrimp, and baby krill. My turtles eat a lot for their size(1inch in diameter)--about 15-20 pieces.