Seachem denitrate 4 L

Seachem De*Nitrate is a high-porosity biological media that removes nitrate, nitrite, ammonia, and organics without risk of hydrogen sulfide production.

Seachem denitrate 4 L

• Removes nitrates, nitrites, ammonia, and organics.
• High porosity biological media.
• Pore size well suited for anaerobic bacteria.
• No danger of hydrogen sulfide production as with sulfur based media.

denitrate is an economical, natural, porous material with a pore distribution and geometry that promotes both aerobic nitrification within the first few millimeters of depth and anaerobic denitrification at the core. The material has a high surface area and supports a high density of bacteria. Although denitrate has capacity to trap nitrate, this, as with other nitrate retaining materials, such as certain zeolites and synthetic resins, is quite limited and the primary mechanism of nitrate removal is anaerobic.

“Live” rocks or reef rocks remove nitrate by anaerobic denitrification. denitrate removes nitrate by the same process. Efficiency is magnified several folds by forcing the water to filter through the porous denitrate. As with reef rock, anaerobic conditions are achieved by the porosity and the depletion of oxygen by the aerobic process at the surface. Excessive flow rates should, therefore, be avoided, as they may impede development of an adequate anaerobic environment to support denitrifying bacteria.

denitrate is also an excellent media for aerobic nitrification and it makes an ideal biological filter in drip trays, canister filters, sumps, or even box filters. At high flow rates (greater than 100 US gallons per hour), it will function solely as an aerobic filter. At slow flow rates (less than 50 US gallons per hour), it will function as both an aerobic filter and an anaerobic denitrifying filter.

The Seachem denitrate 4 L gives nitrifying bacteria a home to colonize as part of your tank's biological filtration — see our guide to the Nitrogen Cycle for how this fits into overall water quality.

See our guide to choosing filter media for how this product fits into a complete filtration setup.

Specifications

A porous ceramic biomedium that supports aerobic nitrifying bacteria at the surface and anaerobic denitrifying bacteria at the core, so one medium handles ammonia, nitrite and nitrate.

Capacity: 500 mL treats roughly 100–200 L (25–50 US gallons), depending on starting nitrate and bioload.

Maximum flow: 200 L (50 US gallons) per hour through the medium.

Expect nitrate to settle at around 4–5 mg/L after several days.

Setup & Use

Flow rate is the whole trick with this medium. Below 200 L (50 US gallons) per hour it runs anaerobic at the core and removes nitrate as well as ammonia; above about 400 L (100 US gallons) per hour it behaves as an ordinary aerobic biomedium and nitrate removal stops.

Suits canister filters, chemical filtration modules, box filters, drip trays and sumps. If nitrate is above about 20 mg/L, bring it down with water changes first rather than expecting the medium to do it.

It never exhausts and never needs replacing, but it will clog with detritus. Pre-filtering the water extends its life considerably.

Freshness & Storage

Every batch we dispatch carries a minimum of 6 months' remaining shelf life. Store this product in a cool, dry place away from direct sunlight, with the cap or inner foil closed tightly after each use.

Filter media and substrates carry no manufacturing or expiry date — their working life begins on first contact with water, not on the shelf.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number — or email us, if you would rather — and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 72 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.