I dip all of my corals in Luguls Solution and then Revive. I use a flashlight to look closely for flatworms or red bugs and a turkey Baster to swish the water and suck out anything I may find. Never trust anyplace - LFS or reefer. Assume every piece has something.
I was not award corals could carry ich though.
I've heard of some people using a UV at least 18w and. 100gph pump. Slower flow is more efficient. It's not 100%. But essentially, when the Ich complete the first phase and drop off you have a shot at killing the free floaters with the UV. otherwise, you're catching fish.
My recco is copper - Cupramine. Hypo messes with the bacteria and causes serious fluctuations in PH, ammonia and nitrite. It's hard to keep up and very likely you'll lose the fish due to all the changes
One thing about copper is some fish are sensitive to it