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White spots themselves can be difficult to diagnose - this certainly could be marine ich, Cryptocaryon. Copperbands are also prone to Lymphocystis virus. These spots are a bit small for that, but they may just be starting. Lymphocystis doesn't need to be treated, ich usually does.
The way to tell them apart is this: watch the spots each day (sometimes by comparing photographs). If the spots are in the same location day to day, it is likely lymphocystis. If the spots come and go, change in numbers, but generally increase in numbers over time, it is most likely ich.
What you should do is prepare for if it is ich; you'll have three options: coppersafe in a treatment tank for all fish, hyposalinity (low salinity) in your main tank if you do not have any invertebrates in there. Or something called "ich management" where you try a variety of techniques to keep the parasite at bay.