Ich in reef tank

[mattr]

Got a fish with some ick on it and I saw that now another fish has signs of it.
I am wondering if a uv sterilizer would do the trick.

I have been feeding them with garlic soaked food that has been vitamin enriched and the stuff is still there...

It is a reef tank with corals and lots of inverts.
Taking the fish out and putting them into a quarantine tank is not a option

Thanks for the suggestions!