If that were my tank I would exume all those Palys that are surrounding the Blastos.
Bubble algae just be careful and take them out for now.
After a while they will stop coming back.
They seem to collect in areas with detritus in the rock work, I think I see another type of green algae on that same rock in the back. If that is the case, I would take the rock out and violently shake the rock out in a bucket of saltwater, get the poo out.
I use water change water since it is going to be thrown out anyways. Really any rock you can remove gunk from you should try when you can.