In my 55 gallon reef I haven't had ich knock on wood bit I have cleaner shrimp that eat it off the fish and I run a huge 40 Watt UV on my tank so I haven't had any issues with it but try to catch all the fish and put them in a qt tank and treat with copper for no less then 6 weeks to help heal the fish and in that time the ich will have broke its cycle in ur main tank and you should be able to put ur fish back in the main as well