How Should a Turtle's Diet Change From Hatchling to Adult?

Young Turtles: More Protein, Every Day

Hatchlings and juveniles build shell and bone faster than they ever will again. ReptiFiles suggests roughly half protein and half vegetables for turtles under a year old, with protein and greens every day and pellets every other day. Young turtles often refuse greens at first; keep offering them, because they'll need the habit later.

Adults: Mostly Greens

As growth slows, the balance shifts. For adults over a year old, aim for about three-quarters vegetables (leafy greens and aquatic plants) and a quarter protein. Offer greens daily, protein only once or twice a week, and pellets two or three times a week. The change is gradual over the second year, not overnight.

Overfeeding is common, and turtles always act hungry. Too much protein can lead to fast, uneven shell growth and an overweight turtle.

Portions and What to Feed

• Protein: what the turtle eats in about 5–10 minutes. Good choices include earthworms, crickets, roaches, freeze-dried shrimp and suitable feeder fish such as guppies. Avoid goldfish, which can cause vitamin B1 problems.
• Vegetables: a pile about the size of the shell. Collard greens, romaine, dandelion greens, endive and aquatic plants are good.
• Pellets: about the size of the turtle's head. A good aquatic turtle pellet is useful but should be no more than about a quarter of the diet.
• Fruit: an occasional treat only.

These are typical figures from keeper guidance; check with your vet or a specialist keeper, because species differ. Box turtles and tortoises have very different diets (see our tortoise guide).

Calcium and Shell Health

Put a cuttlebone in the tank, with the hard plastic backing removed, and replace it every month or two. It gives calcium and helps keep the beak trimmed. Calcium only does its job with the right UVB and basking heat, so diet and lighting work together. Our red-eared slider page has the basking and UVB figures.

Clean Water Matters as Much as Food

Uneaten food and waste foul turtle water quickly, and poor water quality is linked to shell and skin problems. Remove leftovers after meals, run a strong filter, test the water, and do regular partial water changes. Some keepers feed in a separate tub, but moving can stress a turtle, so many feed in the tank and scoop out leftovers.