Should I be worried?

[AndrewB]

I have several patches of these sponges (I think) it’s a mature aquarium (4-5 years) Are these anything to worry about? How do I treat it? If it’s not going to harm my coral or fish then I’ll leave it alone as I think it makes things look “natural”

 

[brmreefer]

No worries needed for sponges. I have some in my system with no ill affects.

 

[Isopod80]

It appears you have a Clathrina sponge. Likely Clathrina clathrus. I have a large colony of this species in my current reef as well as several in past tanks. I've never had any issues with this variety and find it to be quite hardy. Some sponges can be problematic however so it's always best to research. Good luck with them.