Phosphate/Nitrate levels in relation to bleaching

[damura]

Hi all,

I was wondering from your experience or from an article on the web, what are the relations between these 2 parameters to SPS bleaching. Lately i have noticed Cyano bacteria together with SPS sporadic bleaching os my SPS's. Obviously the levels of my nutrients have gone up.
My question is:
From what levels am i suppose to see bleaching? i know that some SPS's are more valnurable than others. I just want to get the order of magnitude, e.g. is it from above 0.1ppm Phosphate or, say 1ppm?
I have also noticed that my alkalinity dropped to 5.5dKh, so maybe i have fluctuations in pH. What inputs or articles can i read about these chemical parameters in relation to bleaching?

Thanks.