I have a tank that has been up and running for YEARS. I have never had any problems, diseases, nothing. I have tons of guppies, a couple pairs of assorted tetras, and a catfish. Over the past couple days I've noticed some of my fancy tail look somewhat shredded. But I assumed it was other males doing it as I've seen the males chase the males and nip at them. Then some of them started showing a white fringe on the edges. Yesterday I bought a Fluval 305 and put it in. Switched my biomedia ( which was FULL ) over and started it up. I have a air pump on the way since there will be no surface agitation so less oxygen, untill then I rigged the return to sit above the water and it makes LOTS of bubbles. I almost immediately lost my emperor tetra, he turned white and very lethargic, less oxygen while I was setting up?? Not sure but. I know they are very sensitive to change and stress. I put him in hospital basket right near the return, his color started coming back but I lost him later that evening. Now I have noticed this morning a couple females have white spots on their back right where the base of their tail is. If I look closely it looks kind of raw. My tetras get along great with the guppies so I don't think it is a injury. I looked online and here on this site ( I'm on here alot and FINALLY joined ! ) and have seen cases where fin rot can look like this. I just need advice...( raise temps? salt? Also have heard dips in peroxide mix help)any help would be appreciated. I will post a pic from my phone in a minute.
