Going fallow is one way to go about it...
There is more to understand which lies beneath a typical catch everything and copper it into the ground approach.
Most ich is brought about by fish stress, and, quite ironically, grabbing fish out, chasing them around, and exposing them to toxic copper is perhaps the most stressful experience you could provide.
Consider, instead, lowing stress. You will see the ich propagate itself among your community, but if your community is fed a nutritious diet, and distressed, you will see their immune system fight ich itself.
Treating ich inadvertently by lowering stress and feeding a super nutritious diet requires less work, typically results in fewer, and, most times... zero, casuallties.
I brought home a new coral beauty at the beginning of November, acclimated it to the 215g, and low and behold ich spread among the 21 fish community - tangs, clowns, bennies, gobies, damsels, wrasses wrapped everything. Remaining calm, I boosted feeding and kept my hands out of the tank for a few days.
Three weeks later, following the above mentioned technique, zero losses... And now the fish are stronger with boosted immune systems.