I would catch the ones you can and treat in a separate tank. For the remainder you could try DR G’s chloroquine impregnated reef caviar. The trick is getting the fish to eat it but if they do you may be able to knock it out. I run my quarantine tank like a mini reef with live rock, mushrooms and some softies as I think the fish acclimate better in a more natural environment. I have been able to successfully treat ich using the above food without affecting the inverts in the tank. Again the trick is getting the fish to eat it. Some will, some won’t. Dosing chloroquine directly into the tank is much much riskier. Tried that once when I couldn’t get my hands on the food with very different and very bad results (brittle star, bristleworm, and other invert die off as well as the sick fish)
Ich is caused by Protozoa which on a cellular level are eukaryotic just like the fish (and people). Most antibiotics work against bacteria which are prokaryotes (fundamentally different metabolically). The antibiotics target these differences, sparing the fishes (and our) cellular metabolism making them safer for the fish. Because ich causing organisms have the same basic cellular metabolic pathways as the fish, treating is harder and riskier and not all medications will be effective. Most antibiotics that target bacteria won’t be effective.
Chloroquine was originally developed to treat malaria, also a protozoan infection, so it seems reasonable that this would be effective against ich
Ich is caused by Protozoa which on a cellular level are eukaryotic just like the fish (and people). Most antibiotics work against bacteria which are prokaryotes (fundamentally different metabolically). The antibiotics target these differences, sparing the fishes (and our) cellular metabolism making them safer for the fish. Because ich causing organisms have the same basic cellular metabolic pathways as the fish, treating is harder and riskier and not all medications will be effective. Most antibiotics that target bacteria won’t be effective.
Chloroquine was originally developed to treat malaria, also a protozoan infection, so it seems reasonable that this would be effective against ich