I have been running the natureef system for about 9 months. Currently my nitrates are around 5ppm. But I am still having phosphate issues (usually around 1.0-1.6). In the last couple of weeks I have notice a large decrease in macro algae in fuge, and within the last couple days tha bacteria in the natureef chamber has been falling off the walls of the chamber. There is now a bed of around 1 inch deep of bacteria. The bacteria is still the same color as it was on the walls so I am assuming it is still alive.
I will note that I have been running GFO and carbon, but at a slow rate. Two BRS RO containers (both about half filled) on system that is around 400 gallons total volume.