Cowfish with Ich

G'day,
I have to admit, I rarely come here unless I have problems, but appreciate the help you guys give. In my 220L tank I have a small longhorned cowfish (about 2 inches), a juv Koran Angel, a Flame Angel, and 5-6" Foxface (yes I know I'll need a bigger tank when they approach maturity).

The Cowfish has come down with what I think is Ich. It looked sort of like it had been rolled in salt at and it's fins were almost worn off at it's worse. This happened in 2 bouts. It pretty much cleared up, then came back while it was in the display tank (This was over around 2-3 weeks since it initially appeared). I failed to find any medicine that I felt comfortable using.

It stopped eating at this stage and was getting darker colour, and since it can hurt the other fish if it dies, I moved it to an old 1ft (20-30L) tank which I filled with tap water / prime / instant ocean of the appropriate levels. The PH/salinity tested right at 8.4/1.024 and the temp is 26.5c. I've changed about 50% (a bucket) a day while vacuuming the bottom (including a lot of dots).

It's now a week later, and the dots have cleared up (both on the floor of the tank and on the cowfish) and it's turned bright yellow again and is eating.

The only other infections in the display tank have been 1 or 2 dots on the Foxface which have now cleared up.

I understand the cycle for Ich.. but the problem is I think it's always going to be in my display tank because I can't remove all the fish from it.

Any suggestions on whether I should move the Cowfish back to the display tank or keep it in this tiny "hospital" tank and try and treat the display tank somehow?. The display tank has inverts and liverock so I think most medication is out of the questions .

 

if it is cleared up and eating well go ahead and put it back. just keep an eye on it. and maybe get a few 6 line wrasse or some cleaner or fire shrimp to help with the prasite left in the tank. good luck