I have a 7-year-old Shubunkin fish who was housed in a 20 gallon long tank. I recently upgraded to a 40 gallon long tank. Before I transferred her, I noticed white fuzzy spots on her fins and treated her with Furan-2 in the 20 gallon. She has had the white fuzz for several months (predominantly on the tail fin) despite bi-weekly water changes. The white fuzzy spots seemed to disappear after the treatment and I moved her over to the cycled 40 gallon tank yesterday. This morning, I am noticing 3 white fuzzy spots on the edge of her Pelvic fins when the majority of the white fuzzy spots were on her tail fin prior to the treatment. The spots on her tail fin are gone. She has long, fancy fins so they occasionally rip or tear (probably due to getting caught in the filter) so I attributed the white fuzz fungus to the tears/rips on the fins. Not sure what to do so any help would be greatly appreciated!