PolypLab Medic peroxide salts works in temporarily treating your fish and lowering ich population; however it won’t eradicate ich.
The only way to eradicate ich is to copper or hypo treat all your fish, and leave your tank fallow for 6-8 weeks (coral and inverts can stay in the tank).
Then, moving forward, quarantine everything that goes in your tank (ie fish, coral, inverts, rock etc.). Even a small frag can introduce ich to your system.
Unless you’re done adding stuff to your tank and willing to go fallow, I would just soak your food in Selcon and garlic and let your fish build a tolerance to ich. Quarantining new fish is not so hard, but quarantining everything takes some real discipline that many people don’t have, including me.