Welcome to the fourms
If you use the search function on this forum you will get a ton of info on ick treatment. Also take a look at the reefcentral.com fish disease treatment forum, lots of info there.
I'll give you a few basics;
-ick has a known life cycle. part of that includes the spots dropping off and disappearing, this does not mean the problem is gone, just means the next wave is coming soon.
-You can either seek to "eradicate" or "manage" ick. learn what those terms mean and what interventions go with which approach, choose an approach and stick with it.
-To eradicate ALL the fish need to be treated with copper, hyposalinity, or the tank transfer method. The display system that they have been in is infected at least as much as the fish, this needs to be left fallow for 8-12 weeks before the fish are returneed. That's it, there is NO REEF SAFE MED that actually works.
-To "manage" ick, reduced stress, feeding garlic, UV, cleaner fish/shrimp, using "reef safe" meds, playing soothing music around the tank... are all things suggested for managment. Some of them do nothing at all, but people will tell you otherwise (they are wrong
) Some people are "successful" with management over time, but the parisite is never eliminated and has the potential to pop up and take a toll any time. IMO the term "successful" is debatable in this context.
Now go find that search option and use it. This topic has been covered over and over....