Peroxide is an oxidizer and wont do a thing as ich management in this case is a short cut and UV unit will not erase ich but address what passes through the sleeve and will break down peroxide.
Your chosice is Hyposalinity ( salinity at 1.009) IF . . you Dot have inverts or coral). If you do - You must quarantine and advised is coppersafe at treatment level 2.25. Please posts pics or video under bright white light intensity to confirm ich.
A quarantine tank can be as simple as a tank from a second hand store, a rubbermaid style tub or a starter kit from Walmart which most of the needed essentials. I have a small bucket I can do copper in how long should I leave him in copper?