Granular Ferric Oxide 32oz | GFO | CoralVue
Phosphate Adsorption Media for Fresh and Marine Aquariums
Granular Ferric Oxide commonly refereed to as GFO ideally suited for filtering out phosphate from the water column which promotes better coral growth and helps prevent algae outbreaks. This medias porous high surface area is not only ideal for binding phosphate but also silicate, arsenic and other water-staining compounds.
Granular Ferric Oxide (Gfo) is the only chemical utilized by most reefers to reduce Phosphates (PO4). Elevated PO4 levels bring undesirable algae of all types and colors. These high levels are also detrimental to coral growth and color. This is the area that is typically the biggest struggle for many aquarist. Natural Seawater has PO4 levels below .01.