I learned the hard way about ich and had to tear my reef apart to get a royal gramma out of the rock work early on. It's a PITA, but it's not impossible, especially with smaller tanks. Once you do it once, you'll learn that it's just easier to quarantine everything the right way so that you never have to tear your reef apart to get a fish out. Most new fish (especially fish for your 40 gallon tank) can be quarantined in a 5 gallon tank that gets set up only when you need it. You can get a fluval spec for $35 and it has practically everything you need except for the heater and medication. A 5 gallon bucket, a rio pump and a heater would also work. Also, RSCSP can be mixed ahead of time if its just going in a fish only tank. The fish doesn't care if the calcium precipitates out.