Hi Kitty
Lots has happened since I last posted - now the only fish remaining of those I bought is one panda cory, and five of my nine neons (moved over from my smaller tank) died too. On advice from the emergency forum and a local friend with many years experience, I am treating now with Myxazin, and I hope that the worst is now over.
My water parameters are good - pH is steady at 7.4, ammonia 0, nitrite 0, nitrate between 40 - 80 ppm. I did all the acclimatisation steps correctly, apart from letting a little LFS water in the tank.
Consensus of opinion is bad stock from the LFS. This is backed up by my observations on Friday, when I went in to get more myxazin - there were still about 20 cories in the same holding tank, and almost all of them had ragged tails and dorsal fins, and they were not as active as I would expect.
So the lesson is well and truly learnt on quarantine procedures, but I am not going to think about adding more fish until a couple of weeks after the medication is finished and I am satisfied the problem is resolved. I know a lot of the bacteria in the filter will have died back so restocking slowly will be important. It seems a shame after completing the fishless cycle, but I think it is the only way.
Thank you all for your helpful comments and suggestions, I'll have some more questions about stocking in a few weeks.
