They eat greens and raw vegetables, worms, hard-boiled eggs, and cat food. They do not need to eat any more than twice a week. In the winter, they are often less hungry although we have a heat source under their cage. We keep them in an aquarium lined with clean newspaper. There is a box for a house and a low dish that they can climb into for water.
Some people prefer to build more naturalistic habitats using earth and plants.
I have found this difficult to keep clean and prefer the newspaper lined home. Turtles are messy, and need frequent cleaning. Water turtles tend to eat more meat and fish than the terrestrial species, but they love their vegetables too. Sometimes I give her bits of raw meat or fish. In her plastic pool, we provide a block of calcium for her to chew.