can ich be dormant in a tank?

[jacksonpt]

I had an outbreak of ich a couple of weeks ago. 2 of my fish died, 2 caught ich, but seem to have come through and are healthy again. They are in an established reef, so removing them for treatment is very difficult. I am still trying though.
Can ich still be in the tank without showing visible signs? I know about the 23ish day livespan of ich, but I'm wondering if/when I will know when it is OK to replace the fish I lost.

 

[beth]

Once ich is introduced into a tank, it remains in the tank as long as fish remain in the tank.
Ich is not really domant, but it can be held in check as healthy fish fend off the infection. However, its a ticking bomb.