Water type
Marine + Freshwater
Replace every
3 months
Media type
Iron hydroxide
Media volume
800 mL
Removes
Phosphate, silicate
Dose
500 mL per 300 L
Lasts
3 to 6 months
Aqua Medic Antiphos Fe 500g/800ml
500 g of iron-based GFO, sized for a 300 L system. This is the 500 g (approximately 800 mL by volume) pack of Aqua Medic Antiphos Fe, an aluminium-free iron hydroxide media that binds phosphate and silicate to starve nuisance and diatom algae. It suits both freshwater and marine set-ups, including reef tanks carrying corals and invertebrates.
Key features
- Binds phosphate and silicate – removes the nutrients nuisance algae rely on.
- Aluminium-free – iron hydroxide chemistry, not an aluminium oxide media.
- Rated for a 300 L system – under normal bioload, for roughly three to six months.
- Fresh or marine safe – suits reef, FOWLR, planted and community systems.
Specifications
| Weight | Approx. volume | SKU | Barcode |
|---|---|---|---|
| 500 g | 800 mL | AB11651 | 4025901142423 |
Setting it up
Rinse before use. Run in a fluidised reactor for best contact, or a mesh filter bag in good flow if you do not run a reactor. Test phosphate on a schedule and replace once the reading plateaus rather than waiting for it to climb back up.
Suitable for, and not suitable for
Suitable for phosphate- or silicate-driven algae in freshwater and marine systems up to roughly 300 L at normal bioload. Larger or heavily stocked systems will exhaust this pack faster – for those, see the 1000 g Antiphos Fe pack.
Warranty and delivery
Covered by the manufacturer's standard shelf-life guarantee, in addition to your rights under Australian Consumer Law. Ships standard parcel from North Lakes, QLD.
Common questions
How long does 500 g actually last?
Aqua Medic rates it for a 300 L aquarium under normal bioload for roughly three to six months – heavier feeding or stocking will shorten that.
Can I mix it with carbon in the same reactor?
Run them in separate chambers or reactors where possible – it keeps contact time and flow correct for each media rather than one starving the other of flow.
Is it safe for shrimp and other invertebrates?
Yes, when rinsed and run as directed. It does not add anything harmful to the water column – it is binding phosphate and silicate onto the media itself.




