Thanks Eric, I am doing a full clean i.e big water change, filter clean and scrubbing the tank. See how this goes. Cheers

Edit: after another careful look I see that some of the fish have damaged fins (fin rot?) maybe a secondary thing? I am adding some photos. Please send your comments. Thank you

Hi all New cory breeder and member. I have about 25, 200 liter aquariums and three 500 liter plastic tanks. I have been keeping several cory spp. for about three months. Some of the fish have a white growth on their fins and not on any other body part. The growth is rather large white usually round ...