VioletEmber
Aquarium Advice Freak
I am panicking! Is this fin rot? Or worse? Is it contagious? I had an older female guppy in the tank with him and she started looking raggedy so I separated her from her male -- and she died the next day-- her fins looking terrible. Now today I notice this on my beloved perry! I can go test the water- but I've been doing lots of water changes lately because I just switched from gravel to sand in this tank.
I took all the plants and fish out of original tank, put the washed sand in the bottom of a different tank, added the plants and filter and fish, even 50% of the water from the original tank.
He is currently in a 10g with 3 ottos, two guppies and 4 lampeye killifish. If it is contagious, then I should treat the whole tank?