|Re: Help! My fish are dying|
Subject: Re: Help! My fish are dying
by fcmf on 28/9/2020 20:36:11
Sorry - I tried to reply earlier but the site went offline. Also sorry to read about this very sad situation - I also name and get attached to my fish, so I can only imagine the distress your young daughters are suffering. I do hope the baby fish is "hanging on" but it doesn't sound like it will have.
Although you mention "the water tested fine", what brand and type of test kits are you using, and what are/were the exact results? What may seem as fine may have some subtle differences that help make the diagnosis.
I think the crux of the problem is almost certainly the small tank (https://www.fishkeeping.co.uk/articles ... -size-life-expectancy.htm), coupled with a partial fish-in cycle once the new/replacement fish arrived. Essentially, once the previous fish died, the beneficial bacteria in the filter that processes the fishes' waste will have pared back to only process that of the one fish; once the new/replacement fish arrived, the filter would have been struggling to cope with the additional bioload. Careful monitoring of the water quality (ammonia, nitrite and nitrates) at least once a day would be required for the following couple of months, addressing the issue as per https://www.fishkeeping.co.uk/articles ... ammonia-nitrite-spike.htm
Does your filter have any carbon in it? If so, that would impede the effectiveness of the medication.
If, by any chance, the baby fish has died, and your daughters would like new fish, then I strongly suggest that *either* you purchase a larger tank suitable for goldfish and do a fishless cycle https://www.fishkeeping.co.uk/articles ... hless-cycling-article.htm, then stock once that is complete, *or* buy some fish more appropriate to the tank size such as male platies or male endlers, white cloud mountain minnows, or cherry barb tropical fish.