Ick dots and velvet dots look roughly the same however ick tends to be oval in shape and velvet round.
When dealing with parasites like these two, dots disappearing can just be the next stage of their life cycles. After feeding on your fish, they will fall off, go to the bottom, and divide by 100-200 times. Then, this never ending cycle will repeat again and again.
Based on your last post, you do not describe either parasite.
Lathargic, glassy eyes, Not eating, scratching.......any of these?
Check your nutrient levels, I am thinking, new tank, elevated nutrients.
Hope to see nitrate under 30ppm at this point and over the next few months, down to 5-10ppm.
If not, you only have fish so let’s work towards those goals.
You need to keep track of the 5 parameters and ensure they are stable. Temp, Salinity,Nitrate,Phosphate,Ph
if you decide to add Stoney type corals, same process for them, CA, ALK, MG.
I might consider 3 -20% water changes one day apart......Run some activated carbon......
Ensure you are feeding varied and high protein high fat diet.
Pellets usually high in both
Strong fish can withstand disease.
If you want to post your parameters, members can help you more, parameters help rule out certain things.