If you do a search for the reefsafe Ich treatments, you'll find it's hit or miss for some people. In my experience, when I was keeping a reef aquarium, NO ICH and KICK ICH has not worked for me.
Since you have no fish at the moment and if you want to make sure the ICH is gone, run the tank fowl for a minimum of 2 weeks to a month. With no fish as host, the remaining ICH will die off. The typical life cycle of ICH is about 12-16 days depending on the temperature of the tank. If you do a search for ICH, most suggest running fishless for a month to be certain.
Keep in mind that if you don't quarantine new additions, there is the possibility of reintroducing ICH into the tank.
good luck.