MY Nightmare/Miracle......

[phixer]

Were you using RO/DI water? The reason Im asking is because unless the phosphate is removed beforehand it will eventually lead to a gradual rise over time. There are different types of phosphates, one type produces algae and stunts coral growth, it cant be measured because it quickly gets used by the algae in your tank so you would always read zero.
Anything above .05 ppm will cause this. I wonder if the product you used to correct this neutralizes phosphate? Interesting. :thinking:

 

[stsweene]

I had the same green water problem you had and I used Algone and had crystal clear water in a few weeks, I was also using carbon so I wasnt sure which it was that worked the best. But Ive been using Algone ever since and have never had any problems. Its completly reef safe, I attach one to my PH with a rubberband and that seems to work.