Seachem PhosBond
Cost per litre
$0.10
Water type
Freshwater + Marine
Cost per litre
5.3c
Water type
Freshwater + Marine
Cost per litre
4.7c
Water type
Freshwater + Marine
Cost per litre
4.0c
Water type
Freshwater + Marine
Cost per litre
2.7c
Water type
Freshwater + Marine
Seachem PhosBond
Strips phosphate and silicate out of the water column to starve nuisance algae at the source. Seachem PhosBond combines granular ferric oxide with aluminium oxide in one media, removing both phosphate and silicate together rather than needing two separate products. It works in fresh and saltwater, is reusable until exhausted, and never leaches what it's captured back into the tank.
Key features
- Removes phosphate and silicate together – one media instead of running two separate chemical filters.
- Fresh and saltwater safe – the same media, different dose rates for each.
- Reusable – can be removed, dried and returned to service until it's exhausted; it doesn't leach phosphate or silicate back out.
- Won't crash your levels overnight – dosed correctly, it draws phosphate down gradually rather than shocking sensitive invertebrates.
Specifications
| Brand | Seachem |
|---|---|
| Product | PhosBond |
| Composition | Ferric oxide coated aluminium oxide (GFO + aluminium oxide blend) |
| Removes | Phosphate and silicate |
| Water type | Freshwater and marine |
| Saltwater dose | 60 mL per 200 L |
| Freshwater dose | 60 mL per 400 L |
| Use in | Reactor, canister filter, media chamber, box filter or high-flow area of a trickle filter, ideally in a media bag |
| Reusable | Yes – dry and return to service until exhausted |
| Pack sizes | 100 mL, 250 mL, 500 mL, 1 L, 4 L |
Which size do I need?
The dose is the same ratio at every size – 60 mL per 200 L of saltwater, or 60 mL per 400 L of freshwater. Buy based on the size of your system and how often you plan to refresh the media, not just the sticker price of the bottle.
| Pack size | Treats (saltwater) | Treats (freshwater) |
|---|---|---|
| 100 mL | ~333 L | ~667 L |
| 250 mL | ~833 L | ~1,667 L |
| 500 mL | ~1,667 L | ~3,333 L |
| 1 L | ~3,333 L | ~6,667 L |
| 4 L | ~13,333 L | ~26,667 L |
Figures are based on Seachem's published dose rate.
Setup and use
Rinse the media before use, then run it in a media bag inside a canister filter, media chamber, box filter, or the high-flow section of a trickle filter or reactor – anywhere water passes through it without the granules tumbling against each other. Test phosphate after 4 days; if it hasn't dropped to around 0.02 mg/L, leave the media in place and test again in a few more days. Once levels are low, PhosBond can stay in place until they start climbing again – there's no need to run it constantly once your system is stable.
Suitable for, and not suitable for
- Suitable for: reef tanks and FOWLR systems fighting nuisance algae, freshwater planted or community tanks with excess phosphate, anyone wanting to remove silicate alongside phosphate in one pass.
- Not suitable for: dosing all at once at a rate beyond the label – overdosing pulls phosphate down too fast and can stress sensitive invertebrates. Follow the stated dose rather than adding extra for a faster result.
Care and maintenance
PhosBond can be removed, rinsed and dried between uses and returned to service until it's fully exhausted – it doesn't release what it's captured back into the water. Replace it once it stops bringing phosphate back down after a few days in place.
Warranty and delivery
Covered by Seachem's standard quality guarantee at the time of sale, in addition to your rights under Australian Consumer Law. Ships as a standard parcel at every pack size.
Common questions
Can I use PhosBond in a freshwater tank?
Yes. Use half the saltwater dose – 60 mL per 400 L of freshwater rather than 60 mL per 200 L of saltwater.
Will it hurt my invertebrates?
Dosed correctly, no. Overdosing is the risk – it can pull phosphate down too quickly and stress sensitive invertebrates, so stick to the stated rate rather than adding extra.
Do I need a reactor, or can I use a media bag?
A media bag in a canister filter, media chamber, box filter or high-flow area works well – a reactor isn't required, though it can improve contact time on larger systems.
How do I know when to replace it?
Test your phosphate around 4 days after installing fresh media. Once it stops bringing levels back down to roughly 0.02 mg/L, it's time to replace it.
