My fish has extreme tail rot. I put liquid medicine in the tank once a month, but the fish has shown no improvement. They have had the condition for about six months.
You have poor water conditions and have to kick up your water changes. Change at least 50% at least every other week. Do this on a regular basis and diseases, etc. will become a thing of the past. You need to not overstock or overfeed because this causes problems as well. They key is good quality clean water and good quality foods.
are the other fishes fin nipping it?no cure for that.they might not be compatible fish.should be community fishes or they wont get along