White spots on back of my tank?

Hello, i ahve biocube 29, and at the tank, at the back of the tank, there is white spots here and there, and they look like rice. Any guess on what it is?

Sorry no pics, so we have to play pictionary

 

If you run your fingernail over them and they are hard they are most likely spirorbid polychaetes. They are a harmless feather duster worm. They make a calcareous tube in the shape of a spiral.

 

Do you have snails? My snails leave them all over the place. I just scrape em off.

 

my first thought too

I now have my back wall covered in purple and these are showing up again all white on the purple...

that's a possibility too. Do you have nerites? they leave eggs all over the place.

 

I second that thought. They're beneficial if thats what you have.

 

ah ya i have the snails. They may be snail? THey look like rice