I've been using GFO to control phosphates. I had rotator cuff surgery in early nov and it was jan before I could do a water change. Nitrates at zero, p04 was at .003ppm before surgery, got up to .35 before water change. Many things died in the tank. Did a 75% water change, that got me to .08 ppm. Changed GFO, no real improvement. Been using phosphatR in last 2 weeks. No regeneration, p04 is now at .005 ppm. This stuff works. Corals are coming back too.
Kev