Ich update

It's been 10 days since my last post. I have long since reduced the temperature to normal and turned off the UV sterilisers. There's no evidence of ich on any of the fish. I'm inclined to think that the treatment worked.

One problem with this approach, I suppose, is that it permits the parasite to persist in the system. Fish that have recovered from ich acquire some degree of resistance. Reducing the temperature also slows the growth of the parasite. In combination this means that any residual infection would probably be difficult to detect. Ugh. Ironically, the best way to detect the parasite would be to introduce stressed fish that have not been exposed to ich. Unfortunately, that would equate to new fish from the pet store. And, in that case, there would be no way to determine whether they brought the infection with them, or whether they picked it up in my tank. I suppose the best thing to do is to observe the group of baby guppies that were born about a week ago. Not that guppies seem to be terribly susceptible...