Calc. Reactor cause black fuzz on rocks?

[quaz]

Ok, two tanks both with calcium reactors that were left unchecked too long and brought down alk and ph. A brown to black fuzz which seems to have killed the coraline. This sucks, can any one help?

 

[GatorReefman]

Sorry, I don't know either and have them as well. I think increasing the flow may help. Mine have been falling off in chunks and most of my corals seem ok. Just tested my tank parameters: calcium, alkalinity, and nitrates seem within normal limits.
They are really ugly and I would like to get rid of them as well. I have coralline algae still present growing right next to them.

 

[coolie]

Sounds like you have dinoflagellates. I had them and the only thing that rid them was a steady dose of ozone.

 

[LobsterOfJustice]

I hear that running Ca reactors can raise you phosphates (depending on the purity of the media), which would explain the algae growth.