I’m going to treat the tank with prazi prosorry to hear that - (I'm partially guessing here) - I'm gonna say you have several potential things going on that you should address.
The clowns being that thin seems like internal parasites of some sort - consider treating with API General Cure - soak food along with Focus to hopefully treat for those.
You mentioned ich - you need to decide if you want to try to eliminate that or manage it
Your description of your fish initially makes me wonder if you have brook or velvet in the tank as well.
I would do some research and determine how you want to work with whatever is in your tank - keeping in mind the wrasse can be hard to medicate.
There is a fish disease section here at reef2reef - consider spending some time reading the information in the stickies in that forum.
I’ve been using reef medic which is a peroxide salt and manages/kills off Ich,
I don’t think I have Brooke or velvet, none of the fish look like they have it.
As for the wrasse I’m just going to use reef safe meds in the tank. If things get out of hand I’ll treat them in QT.
I’ll take a look, thanks