[danny zubot]

I knew you'd ask that. You should read up on it before attempting, but I'll give you the low-down.

Place ALL fish (because they will all be carriers even though they may not show symtoms) into Q-tank.

Gradually decrease the salinity over a few days (maybe a week, i can't remember). This is done with small water changes. Stop when you get to 9-11 ppt (again I don't remember) All inverts including parasites will begin to die off at around 19 ppt

You will actually notice the ick fall off of the fish and die. Leave salinity at the low level for a couple days, then very slowly increase the salinity back up to desired level.

I did mine over 6 weeks because that is beyond the life expectancy of the ick in their dormant state.

This method also benifits the fish who might be under stress from the parasites. By decreasing the salinity you are also decreasing the fish's osmotic rate, essentially making it easier for them to breath.

Be careful though, some fish will not tolerate lower salinity levels. And please read up on it before attampting, I'm second guessing the numbers above even as I write this.