i see incurrent
excurrent siphons
tunicate
amazing
thats easier said than done from the perspective of someones tank not being overtaken , saying that they look fascinating. not like a tangled mess of algae, a benthic dominance war is featured here.
whether or not those have photosynthetic inclusions remain to be seen, never underestimate relationships on the reef but these are opportunistic, filter feeding hitchhikers.
tunicate invasion or unidentified spongiform invasion is rare in reef threads thats why I said this is amazing. its really neat and it thrives off suspended particulate feed (and possibly light) but with those active water pumping mechanisms its a heterotrophic feeder
so, in my opinion we have to remove it directly, if you would, take out a test rock of it, pour some peroxide across it, wait 1 mins, rinse off and put back exactly as is do not scrub. there is a strong chance you could have a fix like this. out of a thousand tanks documented online with intricate peroxide dosings, this is the first ever seen for invasive tunicates.
the macro on those things is rare and amazing, snap lots of pics. really I hope you get it balanced but that animal is worth cultivating in another tank, biotopers would trade gold for something that resilient. obligate hitchhikers can wane over time but the larger the reef the more consistent the water table typically, that could be months or years.
there is some fish that will graze pretty much anything in reefing, we should search for that. pro a chaetodon sp