Continuum Aquatics Reef-Basis Captiv Phos Fe - Highly efficient ferric Oxide Filtration Media for Safe and Effective Phosphate Removal in Marine, Reef and Freshwater Aquaria 300-g

GFO is one of the most effective methods of decreasing phosphates in an aquarium and thereby minimizing nuisance algae. Simply pour in a mesh bag and place in a high flow area of your sump, overflow or tank. Like all GFO brands, you will want to rinse the product thoroughly before use. Under given instructions, this GFO will likely drop phosphate levels by 2-3 ppm in 24-48hrs. As GFOs go, this brand is a reasonable value.

I like the product. I just reordered more yesterday to have on hand. Removes phosphates quickly.

Helps mitigate some of the Phosphate but not an absolute remedy.

My reactor was not capable of tumbling this media as the media is pretty heavy. But overall great price

GFO is useful in decreasing phosphates and silicates from your reef tank. You can use commercial mesh bags or, as I do, a hunk of old panty hose. Remember to rinse out product under running water to get out all the dust before using it in your tank.