So, I found the best thing to treat ich. Ginger powder! I also add garlic powder for immunity. I found this on a you tube video about a year ago. You sprinkle a few shakes of both. When ich was running through my tank it took out 3 or 4 fish. I was desperate. I started using it and it worked. Now I use it everyday. More ginger if I’m adding a new fish or I’m in the tank stressing those guys out. Best $10 I’ve spent in a long time. I also have a diffuser for hydrogen peroxide. I also purchased a hydrogen peroxide doser. It’s basically a clay pot that holds a container that slowly releases hydrogen peroxide in the water. One of the two additions completely eradicated ich from 230 gallon tank! Good luck!