you should be feeding your turtle a VARIETY of foods. just think, we eat many many different types of foods throughout the day. so should all animals! one source of nutrition is first of all, hardly complete, and secondly BORING!! so, since your turtle is 5 inches, it should be eating a wide variety of veggies every day. like carrots, squash, cantaloupe, straberries, grapes, green beans, mustard greens, collard greens, green peppers, etc. and then you can use a commercial food, but you must also supplement with live prey. they get a lot of excercise out of chasing down the prey, plus its STIMULATING for the animal. so, goldfish, mealworms, snails, tubifex worms, earthworms, etc. you can also give VERY small amounts of meats and commercial dog and cat foods, but like i said very small amounts, like a treat. also an egg with the shell crushed up is another good food to feed. and a rule of thumb on how much is how much your turtle can consume in 10 mins. also, you should be feeding more veggies and fruits vs. the other stuff because too much protien can cause obesity and shell deformities. and plus, the veggies are where all of the vitamins come from.
meagan