I've been noticing this white build up on the sides on my one serpae tetras. He is still alive right now but I want to know what I need to do to get it off him or prevent it from reaching the others. I don't think it's ich, I've had that before and I though a steady temperature in the tank fixed that. It's not spots but just one solid white film on my fish. What is this, and is there anyway to fix it? I have been looking on this forum with a salt method, is that ok to use if I have plants?