Need help to ID these flatworms

[stlamarc]

Hi all,

please help me id these criters which are everywhere in my sump. I didn’t see any in my display tank yet. Are they bad and should i just siphon them out of there?

thanks in advance
Stephan

 

[Tim'sReef]

Are they moving? On the photos it looks more like sponge to me.

 

[vetteguy53081]

Looks like nerite snail hatchlings if moving otherwise may be spores from sponge. Either can be scraped off glass with an old credit card into a net and discarded

 

[stlamarc]

Thanks for the quick reply guys. I was afraid it was something bad