What are these growing in back of our tank?

[346700984]

What are these in the back of our tank? They look like snails, but they don’t move. They’ve been back there for a few months now. Thanks!

 

[Isopod80]

They appear to be a type of Formaniferan. Harmless filter feeders. I've never seen such a crop.

 

[JGT]

Benthic formanifera.

 

[346700984]

Wow, interesting! Thank you very much! Yes, there are a lot of them!

 

[Isopod80]

Wow, interesting! Thank you very much! Yes, there are a lot of them!

Your tank must be doing well. Formaniferans tend not to fare well otherwise.