I have a huge colony of birds nest and it has been thriving and growing for almost a year and a few days ago I realized that one of the branches was pure white with no polyps, and today there was a little algae on it so I went to blow it off and no joke a bunch of “green dust” or polyps come flying off and a bunch of branches now have no polyps on it and are white, what could cause this? It has been doing great and is in the same spot it always had been, alk 9.0 calcium 490 magnesium 1380 phosphates 0.05 nitrate 4 , I have recently been dosing vibrant as well