CP will kill all of the ich. 100%. Plan to keep your display tank medicated for 90 days. No inverts or corals while the medication is in the tank. No carbon or water changes either. After 90 days, your fish will be healthy and parasite free. On day 91, do a 33% water change and start running carbon. The more the better. On day 95, do another 33% water change. Replace the carbon. On day 99, do another 33% water change, replace the carbon again. On day 100, add 3 cheap snails. Wait 7 days and if they are all alive, you can add back you corals and other inverts. If not, do another 33% water change and replace your carbon. Hint: I only replaced 20% of my water and ran carbon for a week. The snail test failed. Waited another week and replaced the carbon. Got some more snails and this time, they lived. Tank has been fine for 7 months since. Happy reefing!