OK, I've been experimenting with upping and upping the vinegar dose for my tank. Hoping to stop any green algae on the glass and kill off some macroalgae and maybe bryopsis (which has not worked).
I've been adding more and more vinegar and less and less vodka.
Well, at the recent limit of 410 mL of lime-saturated vinegar, the tank really was noticeably poorer.
Most particularly, the RBTAs browned up (still orange, but darker and the white parts are now brown) and they expanded less and less, and the H. crispa also expanded less. Some soft corals were also shrunken.
Cyano also started to grow faster again.
Also, the green algae on the glass seemed to grow faster! Bryopsis is also out of control, although that may not be related.
So I’ve decided to cut way back and try 150 ml of lime-saturated vinegar with no vodka for a bit and see if things go back to normal.