Ok, my issue started either with new stock (all dead and LFS changed supplier because of this batch they got in- they never figured out what was wrong but most of them died like mine- no obvious consistent signs of a particular disease) or a water change which was too quick and might have shocked/ stressed my fish. I have posted before under topic Goldfish mouth stuck open But issues have changed and I really need some advice and diagnosis. Currently 3 Shubunkin are sick. I had these since last year. Here are pics: All 3 are lethargic and sitting at the bottom constantly, were very easy to catch and have slight balance issues: 1st fish: last one to get ill (yesterday), funny shape I think? Might have blood red 'bruise' on its side but difficult to tell due to its coloration. Not interested in food. Fins are frayed with several clean cuts 2nd fish: 2nd to get ill (about a week ago), dropsy and blood red bruise under its belly not eating 3rd fish: 1st to get ill, eating very quick but only if pellets sink beside him. Nothing else. So far I have tried water changes, salt- the dropsy fish improved for a day or so, than back to lethargic. I have quarantined and dosed the med in the pictures. At this stage I am not looking for advice what I should not have done as I was lost for a solution. I am looking for ideas of how you would have treated and for ideas what this could be??? 1000l pond in greenhouse (aquaponic system), running for over a year 9 Shubunkin including 3 sick ones in quarantine Nitrite 0 Ammonia 0 Nitrate 10 I have checked for stuff leaking in anywhere-don't think this is the issue. Likely the new stock has brought something in but what is happening???