How quickly can ich spots form on fish?

[MnFish1]

When it comes to R2R, I take Jay and Randy’s word as the gospel.

From what I read, the fish that don’t well in copper seem to die off in the first week, so perhaps there is no further danger running a 30 day copper treatment than a 14 day on more sensitive fish. Like wrasse…

I could be wrong, I often am.

This I think is correct and agree that there is no further danger with 30 vs 14 days. - however, I would also say that most deaths within the first week are not from copper, but rather other issues.

 

[MnFish1]

Ok, i woke up this morning and the spots on my midas blenny were just sand, however it would appear my six line wrasse was still infected and had formed some small cysts two at max overnight, i have caught it and put it back in my quarantine tank. None of the spots dropped off as i counted them and the other fish are all completely clear, do you think they could’ve been reinfected overnight or should they still be fine. Basically i am asking should i take all out to re quarantine now for 30 days or just the six line

I don't remember your exact situation - however - yes - spots can 're-develop' overnight - and - yes, if its cryptocaryon all fish should be re-treated and the tank left fallow for 6-8 weeks. The question is 'is it cryptocaryon'? Glad the Blennie was sand. Given all that you've said - I would tend to watch - sand is gradually going to go away (lets pretend thats what's on your 6-line) - Ich will come and go - usually gradually getting worse. I would watch - if you're going to treat one you should treat all. Without more information (like how/when was your last QT, was anything else added, are there other symptoms) I hesitate to just say 'sure go ahead and re-treat all of them'. However, my guess is that may be the eventual result, Please keep us updated!!!

A picture might help of the fish.