GFO (Granular Ferric Oxide)

How Often Should I Change My GFO & What’s the Most Effective Way to Use It?

How Often Should I Change My GFO and What's the Most Effective Way to Use It?

GFO (Granular Ferric Oxide) is one of the most common ways to combat high levels of phosphates in a reef tank. Phosphates are predominantly the result of biological waste (i.e. fish poop). They are also commonly found in fish and coral foods, untreated water sources, substrates, additives and even other chemical filter media. While coral, How Often Should I Change My GFO & What’s the Most Effective Way to Use It?