any idea what these are?

[Whatskillz]

I don't know what they are. They don't seem harmful. Have been in the tank for about 8 months but their starting to grow in my sump. No refugee. So they don't need light.
There kinda soft and break up easily

 

[bhodges82]

It's a type of sponge, they are filter feeders.

 

[Whatskillz]

Any way to get rid of them?

 

[ActiveAngel]

If they’re a sponge and you’re determined to get rid of them, then Erythromycin or Chemiclean will wipe out most sponge species. But those are harsh chemicals and may risk affecting other species.

Because these sponges are seemingly harmless (or potentially beneficial), I would not recommend the use of these chemicals.