Seachem DeNitrate

Seachem Denitrate

Seachem Denitrate is an economical, natural, high-porosity biological filter media designed to remove nitrates, nitrites, ammonia, and organic waste from freshwater and marine aquariums. Its unique pore structure supports both aerobic nitrification at the surface and anaerobic denitrification at the core, allowing a single media to perform the full nitrogen cycle in one compact unit. Unlike sulfur-based denitrification media, Seachem Denitrate carries no risk of hydrogen sulphide production, making it a safer and more reliable long-term solution.

The mechanism behind Seachem Denitrate mirrors that of live rock and reef rock in a natural marine environment, where nitrate is removed through anaerobic denitrification deep within the porous structure. By forcing water to flow through Denitrate rather than around it, this process is replicated and significantly magnified, delivering efficient nitrate removal in a fraction of the space.

Key Benefits

• Removes nitrates, nitrites, ammonia, and organic waste biologically
• Supports both aerobic nitrification and anaerobic denitrification in a single media
• High surface area accommodates a dense and diverse bacterial population
• No risk of hydrogen sulphide production unlike sulfur-based alternatives
• Natural, economical, and long-lasting — does not exhaust while nitrates remain controlled
• Suitable for canister filters, sumps, drip trays, box filters, and chemical filtration modules
• Works in both freshwater and marine aquariums

Dosing Instructions

Use 500 mL per 100 to 200 L of aquarium water, depending on initial nitrate concentration and biological load.

Place Seachem Denitrate in a canister filter, chemical filtration module, or box filter to ensure water flows directly through the media rather than around it. Flow rate should not exceed 200 L per hour — at flow rates above 400 L per hour, anaerobic denitrification cannot establish and Denitrate will function as an aerobic filter only. If higher flow rates are unavoidable, Seachem Matrix™ or Pond Matrix™ is recommended instead.

Rinse off dust before first use. After several days, nitrate levels should begin to fall and gradually stabilise at around 4 to 5 mg/L. If nitrates are initially very high, reduce them to below 20 mg/L with water changes before relying on Seachem Denitrate alone. As long as nitrate levels remain controlled, the media is not exhausted and does not need to be replaced.

Flow Rate Guide

Available Sizes

• 100 mL
• 250 mL
• 500 mL
• 1 L
• 2 L
• 4 L