Reef Endurance GFO Phosphate Adsorption Media (CLOSEOUT)

Reef Endurance GFO Phosphate Adsorption Media

Reef Endurance GFO is a granular ferric oxide (GFO) media designed to pull phosphate out of your water column. Phosphate feeds nuisance algae and competes with coral growth, so keeping levels low is one of the most important things you can do for a reef tank. GFO works by binding phosphate directly to the surface of each granule, keeping it locked out of the water.

This media also adsorbs silicate, arsenic, and other water-staining compounds, making it useful beyond just phosphate control. Its porous, high-surface-area structure gives it strong binding capacity per gram. Use it in an up-flow media reactor at around 100 gph (400 l/hr), or place it passively in a fine filter bag or media basket in your sump. Always rinse the media until the water runs clear before use.

Key Features

• Granular ferric oxide (GFO) formula adsorbs phosphate, silicate, and arsenic from the water column

• Porous, high-surface-area granule structure maximizes binding capacity

• Compatible with up-flow media reactors at approximately 100 gph (400 l/hr)

• Also suitable for passive use in a fine filter bag or media basket

• Starting dose of 1 tablespoon per 10 gallons makes it easy to dial in

• Maintenance dose of 2 tablespoons per 10 gallons for ongoing phosphate control

• Recommended replacement interval of every 4-6 weeks, or when phosphate levels begin to rise

• Available in four sizes: 1.25 lbs, 2.5 lbs, 4.5 lbs, and 24 lbs

Ideal For:

• Reef aquariums where elevated phosphate is contributing to algae outbreaks or inhibiting coral growth

• SPS-dominated tanks that require very low, stable phosphate levels

• Freshwater planted tanks managing phosphate-driven algae

• Hobbyists running a dedicated media reactor who want a straightforward GFO option

• High-bioload systems where phosphate spikes between water changes

• Aquarists buying in bulk to reduce per-unit cost on ongoing media use

Specifications:

• Media Type: Granular Ferric Oxide (GFO)

• Adsorbs: Phosphate, silicate, arsenic, and other water-staining compounds

• Compatible Systems: Up-flow media reactor or passive use in filter bag/media basket

• Recommended Flow Rate (reactor use): ~100 gph (400 l/hr)

• Initial Starting Dose: 1 tablespoon per 10 gallons

• Maintenance Dose: 2 tablespoons per 10 gallons

• Recommended Replacement Interval: Every 4-6 weeks, or when phosphate levels begin to rise

• Application: Freshwater and saltwater/marine aquariums

• Available Sizes: 1.25 lbs (RE-GFO-SM), 2.5 lbs (RE-GFO-MD), 4.5 lbs (RE-GFO-LG), 24 lbs (RE-GFO-XL)

Instructions:

1. Rinse GFO media under fresh water until the water runs clear.

2. Load media into an up-flow media reactor or place in a fine filter bag or media basket.

3. For reactor use, set flow rate to approximately 100 gph (400 l/hr). Media should tumble gently, not fluidize aggressively.

4. Use the initial starting dose of 1 tablespoon per 10 gallons of system water.

5. Test phosphate levels after 3-4 days. Adjust dose up to the maintenance level of 2 tablespoons per 10 gallons as needed.

6. Monitor phosphate levels regularly. Replace media when levels begin to rise, typically every 4-6 weeks.

Note: Rinse before each new loading. Do not skip this step. Fine dust from unrinsed GFO can cloud the display tank.