Hi all. My mother has 1 gold fish and has had it for about 2 years, She bought 2 other fish and put it in the same tank and a few days later the 2 new fish died. The goldfish is looking quiet bad, it sits at the bottom of the tank most of the day and sometimes has a little swim. randomly he will lean over sideways in a shape of a upside down U. My mum claims he has eaten but I've never seen him eat. Im not quiet sure what I should do. I have done water changes, parameters are good. What are some medications I should use? or what should i do?
thanks
thanks