My year and half old Betta has developed a swollen lump right under his gills.It looks like he has a fat neck.There is nothing coming out of it.It is under his skin.I thought maybe it was some kind of bacterial infection or dropsy but it has not pineconed.I am on my second treatment of kanacyn.This has been going on for over a week.He still swims around ,eats acts normal but he sure don't look normal.He lives in 2 gallon eclipse tank with filter.ammonia zero,nitrites zero and PH 7.2.Is there anything else I can do??Thanks