What if your red ear slider turtle is 1 inch long he wont eat its pellets?

There are a couple of reasons that your hatchling may not be eating. One is if he doesn't have the proper heat and light. RES turtles must have UVA and UVB light in order to digest food. Without it, they will eventually die. They must have heat as well.

If you have the proper heating and lighting for their tank, the problem is probably the food itself. Try "Reptomin Floating Food Sticks" for aquatic turtles, found in most pet stores and "Wal-Mart".