Does anyone have any idea what these white/gray things are on the sand and rocks in my tank? I did a water change this morning, and they were not there. When I got home tonight, they are all over the tanks. They don't move at all so I'm pretty sure they aren't worms. I thought they may be eggs so I Googled all of the fish in my tank, but nothing seemed to match.
I have zebra and leopard danios, blue neon dwarf gouramis, angelfish, otocinclus, golden dojo loaches, hillstream loaches, bristlenose plecos, nerite snails, racer snails, elephant snails, mystery snails. There is also an errant bladder snail that I see from time to time.