<a href=showthread.php?s=&postid=11934529#post11934529 target=_blank>Originally posted</a> by schigara
Granular Ferric oxide is Granular Ferric oxide. It doesn't matter what label is stuck on it. I have used Phosban, Rowaphos and Phoslock and can't tell any difference. They all work very well.
GFO is not a cure all and one should not throw caution to the wind and hope for it to make everything nice again. It can quickly lower phosphate levels, even ones that are undetectable to crappy test kits, but if you keep SPS coral, you should start slow and use 1/4 the ammount of specified dosage and slowly work up to full dose.
If you consider using GFO, you should also address your feeding, water and cleanup crew. If you are overfeeding or not rinsing frozen foods, using tap water or RO/DI with worn out filters and membrane, GFO alone will not cure the problem.