Seachem de*nitrate

• Porous, dual-zone structure – aerobic nitrification at the surface, anaerobic denitrification at the core.
• Reduces nitrate biologically – converts nitrate to nitrogen gas rather than simply adsorbing it.
• No regular replacement needed – unlike chemical media, de*nitrate does not need to be swapped out on a schedule.
• Freshwater and marine use – suits both system types.
• Runs in a reactor, media bag or chamber – flexible placement in canister filters, sumps, drip trays or dedicated reactors.
• Long-term biological filtration – doubles as standard biological media in addition to its denitrifying role.

Seachem states that 500 mL of de*nitrate treats approximately 100–200 L (25–50 US gallons), depending on starting nitrate level and bioload. The figures below are calculated pro-rata from that published guidance and are approximate.

Place de*nitrate in a canister filter, chemical filtration module, box filter, sump, drip tray or dedicated media reactor. Flow through the media must stay below 200 L/h (50 US gal/h) for the anaerobic core to establish and denitrify; above about 380 L/h (100 US gal/h) it will only work as an aerobic biological media. Allow several days for nitrate to begin falling, typically levelling off around 4–5 mg/L. If starting nitrate is above 20 mg/L, bring it down with water changes first before relying on de*nitrate to maintain it.

• Suitable for freshwater and marine aquariums running a reactor, media bag or low-flow filter chamber.
• Not effective as a denitrator in high-flow filter setups – above roughly 380 L/h through the media it will only provide aerobic filtration, not nitrate reduction.

• Does not need to be replaced or regenerated on a fixed schedule, unlike chemical filter media.
• Works best as the primary media in its own reactor or bag, alongside a sponge pre-filter to keep debris out.
• Compatible for use alongside other Seachem media – Matrix, Purigen, MatrixCarbon, PhosGuard, PhosBond, SeaGel, HyperSorb, CupriSorb and ZeoLite – provided each runs in its own dedicated media bag or chamber.

All statutory consumer guarantees under the Australian Consumer Law apply to this product in addition to any rights arising from your purchase.

How much de*nitrate do I need?

Seachem's published guidance is approximately 100–200 L (25–50 US gallons) treated per 500 mL of media, depending on starting nitrate level and bioload.

Does de*nitrate work in a high-flow canister filter?

Not for denitrification. Flow through the media needs to stay below 200 L/h for the anaerobic core to establish; above roughly 380 L/h it functions only as an aerobic biological media, not a nitrate reducer.

How long until nitrate starts dropping?

Seachem notes nitrate typically begins falling within several days of setup and levels off around 4–5 mg/L. If your starting nitrate is above 20 mg/L, reduce it with water changes first.

Does de*nitrate need to be replaced?

No. Unlike chemical filter media, it does not need scheduled replacement or regeneration.

Is it safe to use with other Seachem filter media?

Yes, provided each media type runs in its own dedicated bag or chamber. Seachem confirms compatibility with Matrix, Purigen, MatrixCarbon, PhosGuard, PhosBond, SeaGel, HyperSorb, CupriSorb and ZeoLite.

Is de*nitrate suitable for marine tanks?

Yes, it is suited to both freshwater and marine aquariums.