PhosBond 1 L — Hybrid Anti-Phosphate GFO + Aluminum Oxide 1.19 mg/g | Seachem

Seachem PhosBond 1L is a revolutionary hybrid filter media that combines aluminum oxide and granular iron oxide (GFO) in a single material, creating a synergistic effect for the rapid removal of phosphates and silicates. With a binding capacity of 1.19 mg PO4/g, PhosBond falls between PhosGuard (0.87 mg/g) and PhosNet (1.41 mg/g), offering the best balance between absorption rate, capacity, and value.

Main advantages

• Hybrid GFO + aluminum oxide — combines the advantages of both types of phosphate blockers in a single medium
• Binding capacity of 1.19 mg PO4/g — superior to PhosGuard, economical compared to pure GFO
• High porosity and large surface area — high bonding capacity
• Physical resistance — does not degrade under mechanical stress
• Irreversible bond — does not release phosphates or silicates into the water

Use in reef and marine aquariums

High phosphate levels promote the growth of unwanted algae and are detrimental to coral health. PhosBond absorbs phosphates quickly—reaching full capacity in 4 to 5 days in the presence of high phosphates. This rapid replacement rate is a sign of effectiveness, not low capacity. Seachem recommends continuous use of small amounts rather than intermittent use of large amounts. Seachem's published binding capacity (1.19 mg PO4/g) is tested at pH 8.4 under real aquarium conditions, without artificially inflating the figures. Under reef conditions, no detectable soluble aluminum is released.

Instructions for use

• Rinse before use. Place in a filter bag such as the Seachem The Bag
• Place in a cartridge filter, media chamber, box filter or any high-flow area — do not use in a media reactor (agitation produces dust)
• Dosage: 60 ml (¼ cup) per 200 L (50 US gallons) of seawater or 400 L (100 US gallons) of freshwater
• Leave in place for 4 days, then test the phosphates. If the concentration has not decreased to 0.02 mg/L, replace the PhosBond.
• If the levels remain under control, the product is not depleted — leave it in place and test weekly.
• PhosBond can be removed, dried, and put back into service as long as it is not exhausted.

Comparison of Seachem anti-phosphates

• PhosGuard (aluminum oxide): 0.87 mg PO4/g — the most economical, fast absorption
• PhosBond (GFO + aluminum oxide hybrid): 1.19 mg PO4/g — best capacity-to-price ratio
• PhosNet (pure GFO): 1.41 mg PO4/g — highest capacity per gram
• Aquavitro Phosfiltrum (super-capacity GFO): 1.71 mg PO4/g — the highest capacity on the market

Manufacturer's precautions

• Do not use in a media reactor — agitation reduces the media to dust
• Do not overdose — too rapid a drop in phosphates can stress sensitive corals
• PhosBond is not an ion-exchange resin and does not release anything into the water.
• Under reef conditions (pH close to 8), no detectable soluble aluminum is released.

Available formats

• 100 ml
• 250 ml
• 500 ml
• 1 L
• 4 L

Why choose PhosBond from ReefSolution?

PhosBond 1L offers the best compromise between binding capacity and price for medium to large reef aquariums. Place it in the Seachem The Bag for optimal use. For the highest capacity, consider Seachem PhosNet (pure GFO). For the lowest price, consider Seachem PhosGuard. Monitor your phosphate levels with the Hanna Checker Phosphate or the Salifert Phosphate Test Kit.

Frequently Asked Questions

What is the difference between PhosBond, PhosGuard and PhosNet?

PhosGuard (aluminum oxide, 0.87 mg PO4/g) is the most economical with its spherical shape. PhosBond (GFO + aluminum oxide hybrid, 1.19 mg PO4/g) combines the advantages of both technologies. PhosNet (pure GFO, 1.41 mg PO4/g) has the highest capacity per gram in the Seachem range.

Can PhosBond be used in a media reactor?

No. Seachem does not recommend this because agitation in a reactor reduces the media to dust. Use in a cartridge filter, media chamber, or any high-flow area with a filter bag.

Why does the published capacity of PhosBond appear to be lower than some competitors?

Seachem tests its capacity at pH 8.4 under real aquarium conditions. Some competitors test at very low pH levels with excessive concentrations, artificially inflating the figures. PhosBond's capacity of 1.19 mg PO4/g reflects its actual performance in a reef aquarium.