Hi all,
The tank is roughly 10 gallons (42 litres) and planted, I've got 4 female guppy's, 3 leopard Danios (was 4), 1 baby pleco and some (6) guppy fry.
I treated the tank for fin for with aquarium salt roughly 2 weeks ago, I've done 2 30% weekly water changes since dosing. The fish all look healthy and aren't showing any signs of fin rot anymore and look all healed up.
I did the second water change on Thursday and then Friday evening I noticed one of my Danios had died, his belly was open and looked as though it had ruptured. I checked the fish after the water change and watched them eat, they all looked healthy (including the danio that died and there were no signs of dropsy or a large stomach so no indication of what caused this death). I checked the water parameters and they are all good (ammonia -0ppm, nitrites - 0.25ppm and nitrates 10ppm).
Today, when feeding the fish I noticed one of the Danios had what looked like a cyst/blister on its lip that appeared out of no where. None of the other fish are showing any indication of this ( I've included images to help).
Sorry if the images aren't very clear, this is the best I could do with the danio they're so quick!
Does anyone know what could have caused this and how I should treat it?
Also should I isolate the danio or treat the whole tank?
Thank you 🙂
Arthur