A well-balanced diet for a pet turtle typically includes a variety of foods such as commercial turtle pellets, leafy greens (e.g., kale, collard greens), vegetables (e.g., carrots, squash), and occasional treats like fruit or live insects. It's important to research the specific dietary needs of your turtle species as they can vary. Additionally, providing supplements like calcium and vitamin D3 may be necessary to ensure your pet turtle receives all the nutrients it needs.