
All but one polyp of this coral started lightening up around the end of last year. I thought it may have been because I moved it up just a little into the rock work. So, a few days ago I moved it back down. The lightening started occuring prior to my anemone getting caught in the powerhead so I can rule that out. The only other change was the addition of carbon and the carbon reactor.
Therefore, as of this morning, the carbon reactor has been taken off line.
I thought I had noticed some increased growth in some of my acros since adding the reactor. Additionally I have definitely noticed my green open brain starting to expand more and more lately.

When I first got it would always be expanded. For the last yer or year and a half it stopped expanding. So this is a definite change and perhaps a benefit of carbon.
Also this morning a few heads of my frogspawn are retracted.

My chaeto has also started to brown a little. Perhaps because the carbon is removing some of the nutrients needed by the chaeto. Perhaps the browning chaeto is causing the stress in the tank.
This is the latest in a series of unfortunate events. Is it due to carbon? I don't know. However, it is easy to take the carbon off line and observe what happens.