Q: FP wrote,

My betta has a pinhole in his tail fin. What kind of medicine should I use to fix this? Is this a case of fin rot?

A: A pinhole is nothing to worry about. They happen occasionally and will heal themselves in a few days. Fin rot is a bacterial infection and is often characterized by black or bloodied fin tips, ragged ends or sudden loss of fin. It can be avoided by keeping your water clean and avoiding stressors like ammonia, nitrite and rapid temperature or pH fluctuations. Minor fin rot can be usually be treated successfully with clean water and the betta’s own immune system. Severe fin rot may require medication but because many medications can be quite potent they should be reserved for instances when the fish cannot heal itself.

Click to learn more about Betta fin loss and fin rot.