I have a 3,500 gallon outdoor pond with filter, uv light, and aerator. I have a mix of 7 koi and goldfish. One of the fantails is presenting with multiple small lumps all over its body. I have tried to treat it by adding 40 lbs of salt slowly over 4 days. Then i turned off uv light and aerator and added a bottle of Melafix everyday for 4 days. I did a 30% pond change everyday for 4 days and no luck...lumpy bumps are still there. All of the fish eating well and behaving normally. Can anyone help me? What is this and how do I get rid of it? I have attached a pic of the fish in question.