Overview Seachem PhosNet GFO is a granular ferric oxide (GFO) media crafted for freshwater and saltwater aquariums

With high porosity, expansive surface area, and strong binding capacity, it rapidly reduces phosphates and silicates to help maintain clearer water

Seachem has spent more than three decades translating science into practical hobbyist solutions, and PhosNet reflects that heritage of education, testing, and reliable performance

As a privately owned company led by aquarium enthusiasts, Seachem continues to support hobbyists with products grounded in -world use and solid science

Key benefits in your tank Removal: The porous granules target phosphates and silicates, helping lower nutrient levels in both display tanks and filtration media

Binding: PhosNet binds contaminants strongly, reducing the chance of re-release back into the water column

Dust reduction: The formulation minimizes dust, making handling and routine maintenance cleaner and easier

Filtration compatibility: Use in canister filters, media chambers, box filters, or high-flow areas; a filter bag is to contain the media

How to use PhosNet for results Preparation: Rinse PhosNet before use to minimize dust and particulates in your system

Placement: Position the media to maximize water flow through it without allowing it to tumble or clog flow paths

Dosing and duration: Use 50 g (1/2 cup) per 200 L (50 US gallons) of saltwater or 400 L (100 US gallons) of freshwater

Leave PhosNet in place for 4 days, then test phosphate or silicate levels

Re-treatment guidance: If concentrations remain above 0

02 mg/L, re-check and adjust dosing as needed; avoid excessive dosing to prevent over-treatment

Why choose PhosNet The 125 g package provides a practical, science-backed approach to nutrient control

This media works as part of a regular maintenance cycle, helping aquarists pursue clearer water and stable filtration without relying on harsh chemical additives

The product line reflects Seachem’s ongoing commitment to education and support for hobbyists who value proven performance

FAQ Q: What is Seachem PhosNet GFO used for

A: A granular ferric oxide media that targets phosphates and silicates in freshwater and saltwater aquariums

Q: How should PhosNet be used in a filter to avoid over-treating

A: Rinse before use; place to optimize water flow; run about 4 days and test levels; follow dosing guidelines