Can someone tell me please what is the best solution for a fungus/bacterial infection with my fish. I have a silver dollar that has what looks like fluffy substance on the side of its body. I have been doing 20% waterchanges for the past couple of days and will continue for another week. I only have access to online stores or Better Pets n Gardens 100kms away, and staff to my mind are not that knowledgeable with fish care. Need to know whats medication I should be using please.