Wow, two year old thread resurrected. I have always found this and most threads about ich silly as our fish should never be bothered by such things. We can of course eradicate ich and all parasites, but as we have found out, that is difficult and most people can't seem to do it long term.
I personally feel that ich and all parasites are a normal part of a functional fish and fish need ich just as we need bacteria and can't live with out it.
Healthy fish are perfectly able to live with ich as they have been doing since way before Bernie Sanders started looking for a comb.
Parasites were in the sea long before fish and Jacques Cousteau was there and the fish never minded.
It is also of no concern that most of our tanks are smaller than the sea so the parasites are concentrated and have nothing to do but infect our fish. The more parasites, the stronger the fishes immunity.
I don't consider parasites as pests and neither do the fish. They are just there trying to complete their life cycle and have babies. If they were cute, and they may be, we would be keeping them instead of copper band butterflies.
If they have not bothered my fish in 40 years, you can get your fish to the point where they are of no concern. I have written about this so many times that I am getting Nauseous so I don't want to do it again and no one wants to hear it or believe it. But if our fish are dying from ich, it is our fault, not the fish, the LFS, the wholesaler or Bernie Sanders. (although he may have had a hand in it)
