Black Ick, it's back...

[MitchM]

Yes, 1.009.....or 1.010.
Reduce the salinity over 4 or 5 days to the lower level, and do it in a QT tank. You will kill your invertebrates in the main tank if you do it in there! :shock:
Keep the fish in QT for a month....a full month. Make sure that you keep your main tank WELL fed during this time, as healthy fat fish are less likely to contract diseases.
At the end of the month, take 4 or 5 days to bring the salinity back up again to the main tank level, and re-introduce the fish.
I have found hyposalinity to be a much safer and reliable method for curing fish of parasites than copper.

HTH, Doug!

Mitch