I'm sure you'll get some more experienced people responding, but here's what I remember from my newbie research not too long ago. Without more information, it sounds like diatom algae, which is natural at this time and will eventually go away. I reduced my lighting and vacuumed the sand. The clean up crew should help as well, though you might need some other critters that are more sand oriented to stir it up. I have some turbos, astrea, and nassarius, but some crabs (red-legged I believed are suggested) will work the sand. I didn't have my clean up crew when the sand was covered, but they did a great job on the LR
and glass...all gone in several days. BTW
, watch turbos tend to tip over and can't right themselves very well.
I have found this forum extremely helpful and friendly. There's a wealth of information here!