I have a 155 saltwater reef tank. Sailfin Tang, Power Blue Surgeon, Copperband, two black clowns, two naked clowns, 7 blue green chromis, two bangai cardinals, one purple dottyback, lawnmower blenney, and one neon cleaner fish. 4 fire shrimp, 2 peppermint shrimp, lots of snails, and 4 emerald crabs.

I looked yesterday under a cave live rock and there appears to be a swarm of some microscopic something swimming madly around? What could this be?