I have a male crowntail betta in a 2 gal tank on his own.
The tank has a filter and heater and i change his water every 3 days.
Yesteday i noticed that he had a big white patch under his mouth, so i added a tea spoon of aquarium salt and changed his water. today it has got a little smaller, so it looks like the salt is working. The white kind of looks like cotton wool. It is still rather large.
He isnt eating and im getting worried as he isnt himself at all.
Do you know what it is and what i can do to help him ??