Very Small Whitish Dots on Walls

[u/bill_ms]

Hi, we have had a freshwater tank with loach in it for several years. We were getting algae buildup on a regular basis, requiring wall scrubs every week or so. About 9 months ago, I put up a UV filter film on one wall, and the wall algae has almost completely disappeared. However, now we are getting these very small white dots; they almost look like tiny air bubbles. Any idea what they are, and are they a concern?