So I bought two fancy gold fish back in february this year. They had a nice big tank and were very happy. Unfortunately we moved flat in June, and whilst one was happy and fine my blackmoor, Garfunkel, became very listless and floated around the top of the tank a lot; swim bladder problems etc. Despite careful water changes, keeping the water medicated, peas etc, he recently died. His scales were still completely black aside from the slight orange bits he always had, so he didn't appear to have any diseases; I think he really did just die of stress/distress.
Winston, the pearscales goldfish, is fighting fit and OK. However, we were told to leave it a little while before getting him a new tank mate. How long should we wait?