One of my fish died yesterday, with no obvious swelling (it was a moor) or disease, he just sort of sat at the bottom of the tank and didnt move much, our other fish have done similar things but then are fine.
This morning we woke to discover that one of the other fish (common) has a swelling behind its gill and another on the other side towards the back
here are some pictures, although they are poor as they were taken with my camera phone...
does anyone have any suggestions, we have just a largish standard tank with a big filter, we have also recently had algae growth.
the fish with swelling seems to be normal, but im sure he will get ill....... any tips of the best way to try and fix him?