Skimmer is Deltec Turbo 1250. Alk is 9. Ca is about 350. How do you tell the difference between bleaching and RTN? The Acro Friday just went completely white (it was a Tri-Color). The one Cap I trimmed today (its a pick Cap) had its flesh start receeding around the edges (going white). The other two are starting to get white around the edges, but also seem to be getting "lighter" in spots in the center as well.

All water added to the tank is RO/DI. I'm overdue for a water change, which is happening first thing tomorrow morning. I use Tropic Marin for salt.

No, I don't have a refugium on this tank, just an Oceanic sump with the Deltec skimmer. I also have 2 (2 Little Fishes) reactors in line, that pull from the main area of the sump and outputs back over the tank return area. First reactor has carbon (which I did change Friday night), which then pushes to the reactor with UltraLith.

Did not spray any chemicals around the tank that I know of.

Stephen