Small, round, flat, white critter id?

[Wen]

What are these creatures? Like flat warts!
Not on corals, can’t see them move, located in 3 areas of my tank...seem to be increasing in numbers.

 

[Ilikefishandlamps]

Flat worms

 

[Joe462]

Do you have nerite snails?

They look like nerite snail eggs. They do not look like flatworms

 

[Mr_Knightley]

if they move, then I would guess they are some sort of limpet or stomatella relative. If they are sedentary, thn they are probably sponges or snail egg clusters. Either way, harmless.

 

[Wen]

Thanks guys!
I do have nerite snails, I believe they have a thin shell or hard surface. Will try to pry one off.
Eggs or limpets are ok with me.

 

[Cell]

Nerite eggs.