algae eater has a split tail fin

Hope someone can help, i noticed my alagae eater had a small hole on has tail fin, but now it has split to the end of it. but it has not rotted it is a straight split, does anyone know whats wrong with him, he does not seem to be suffering, thanks

It could be a parasite. Has the algae eater been in the aquarium very long, and is the water chemistry OK?

he has been in the tank for about 3 months. to describe the split its like a pair of scissors has been cut into it, about half an inch along his tail fin.

If it's just a split, those things happen. If it started with a symmetrical hole, a parisite could be responsible. Regular, partial water changes and other good maintenance practices will give the fish a chance to get well without medicating. If it's a parasite or disease he can't fight off, then it's time to consider medicating. Most fish problems cure themselves when the aquarium environment is healthy.

it was a symetrical hole, so if i do 20% change once a week it may help, thanks

The partial water changes will help the fish recover by providing a healthy environment. A healthy fish, in turn, can fight off many diseases and parasites. If aquarium conditions are ideal for a couple of weeks but the fish is not getting better, it may be time to consider medicating. Although I almost never medicate fish or recommend doing it, some people do have success with the chemical cures.