Be confident in your purchase we're an Authorized Simplicity Dealer. How cool is that?!?!? To keep your aquarium clean and healthy, you?ve gotta get rid of the bad guys ? high phosphate levels. Simplicity TB Aquatics GFO, is your partner in fighting the good fight against these phosphates, which can fuel algae and slow coral growth. Granular ferric oxide (GFO) adsorbs phosphates, which leave your finned friends swimming around in healthy coral and less algae. For best results ? and so your fish can live their best life ? use this GFO in a media reactor or in a media bag placed in a high-flow area. Key Benefits: Made from virgin material ? never recycled municipal GFO. Permanently removes phosphate through efficient adsorption. Suitable for use in either fresh or saltwater tanks. With normal use, GFO typically lasts months. Using a media reactor at a gentle tumble achieves best results.