Brightwell AquaticsFerroxiPhos G – Ferric Oxide for Phosphate Control in Marine Saltwater and Freshwater Aquariums, 300-g

Have not tested its ability to remove phosphate, but 3 stars because of how dusty it is even after rinising it multiple times. You get what you pay for.

This GFO is extremly dusty it shot out an orange cloud just from opening the container. It also took over 30 gallons of water to rinse it clean. To be fair though it did lower my phosphates over night from .64 to .36 so it does work. Ill probably just go back to using Aqua Maxx GFO or Bulk Reef Supply.