I have a turtle tank that has 2 turtles in it. The first turtle that I got is bigger that the second one.

Last night after I cleaned their tank and then put them back in, the bigger turtle went to the littler turtle and was bitting its shell. I went to the tank and took out the small turtle and put him in a different tank so that he wouldn't be picked on.

When I was examining his shell I noticed that there were parts of his shell that had broken off on the edge. What should I do? Will his shell grow and fix itself?

I am not sure why the turtles are having a problem now. They have been living together for almost 6 months now.

Please give me some advice....

Unfortunately, turtles sometimes pick on each other. One person put their young painted turtle in with some larger red-eared sliders. The sliders bit off part of the baby's shell and a back foot. The painted turtle died a few months later.

If your turtle is just missing a few of the edge scutes/shell, then as the turtle grows, those should regrow. If the damage is more severe, there may always be a spot with missing shell. Keep an eye out for infection at the injury site. If the injury is minor, it's probably not going to be a problem. If you notice any white stuff or fuzzy stuff (fungus), then it's becoming infected. To reduce the chances of that, keep a tablespoon per 3 gallons or so of aquarium salt in the tank water. Be sure the turtle has plenty of calcium. You can dust insects in reptile vitamins, feed things like kale, and/or put in a cuttlebone to chew on for calcium. I do all three.

How big are your two turtles? What species are they? How big is the tank? If the turtles are becoming mature, it could be a sexual or territorial thing.

Good luck!