If the anemone is stressed -- which this one seems to be -- increasing the bacteria (( which carbon dosing basically does )) can increase the stress and in some cases even push the anemone over the edge.
Years ago, I have a blue S. haddoni. It stressed spawned (( emergency back surgery, sump ran dry, salinity jumped to 1.031, temps spiked to high 80's, { freak heat wave in March } and then dropped to around 70* )), but I managed to get things back under control, though it was still "off". For some reason I tried a bio-active salt (( pretty much the same thing as carbon dosing )), and things took a turn for the worse, and I lost it. Granted, with hindsight it was easy to see.
Ended up taking to Randy (( the chem guru )) about this and he had similar results with carbon dosing and an H. crispa (( believe that was the species )) -- not 100% if it died or not.
Anyways, I would advise against doing that at this point.