Matrix 500 ml — Biomedia 700 m²/L Nitrification and Denitrification | Seachem

Seachem Matrix 500 ml is a high-porosity biomedia designed for efficient biofiltration and nitrogen removal in marine and freshwater aquariums. This 10 mm diameter porous inorganic solid provides a surface area of ​​over 700 m² per liter—the equivalent of 170 liters of plastic beads. Unlike plastic biomaterials that offer only an external surface, Matrix provides both an external and internal macroporous surface with pores sized to simultaneously support nitrifying and denitrifying bacteria.

Main advantages

• Surface area of ​​over 700 m² per liter — equivalent to 170 liters of plastic pellets
• Internal and external macroporous surface — supports nitrifying AND denitrifying bacteria
• Simultaneously removes ammonia, nitrites AND nitrates in the same filter
• Completely inert — does not degrade, never needs to be replaced
• Rinseable without damaging bacteria — the majority are lodged inside the pores
• Compatible with all types of wet or wet-dry filters

Use in reef and marine aquariums

Matrix is ​​unique among biomedia because its macropores support both aerobic bacteria (which remove ammonia and nitrites) and anaerobic bacteria (which reduce nitrates). This dual action allows for complete biofiltration in a single filter. Seachem recommends placing the biological media last in the filtration order: first mechanical filtration (foams, filter floss), then chemical filtration (MatrixCarbon, Purigen, PhosGuard), and finally biological filtration (Matrix). It does not affect the aquarium's pH.

Instructions for use

• 250 ml of Matrix per 200 L (50 US gallons) of water
• Rinse before use
• Place in a cartridge filter, media reactor, box filter, or any high-flow area of ​​the sump
• Large enough that a filter bag is not required in most applications
• Particularly effective in a canister filter
• Use with Seachem Stability to establish the biofilter more quickly

Interview

The Matrix filter does not wear out and never needs replacing. However, it can become clogged with debris and biofilm. Seachem recommends regular filter maintenance—about once a month as a starting point. Since the majority of bacteria are inside the pores, the Matrix can be rinsed to remove debris without damaging the biofilter.

Matrix vs. denitrifying bacteria

If Matrix keeps your nitrate levels stable but doesn't lower them, increase the amount of Matrix or add Seachem de*nitrate, which removes nitrates more efficiently per unit volume at a flow rate not exceeding 200 L/h. For higher flow rates, continue using Matrix, which supports anaerobic denitrification at higher rates. The necessary anaerobic bacteria typically take a few weeks to develop.

Manufacturer's precautions

• Does not affect pH
• Completely inert — does not degrade
• Do not use in runoff tray systems — Seachem Pond Matrix is ​​better suited for these applications

Available formats

• 250 ml
• 500 ml
• 1 L
• 2 L
• 4 L

Why choose the Matrix at ReefSolution?

The 500ml size is the ideal starter pack for medium-sized reef aquariums. To quickly establish your biofilter, combine Matrix with Seachem Stability. Complete your chemical filtration with Seachem Purigen for nitrogenous organics and Seachem MatrixCarbon for organic compounds and colorants.

Frequently Asked Questions

Should The Matrix be replaced?

No. The Matrix is ​​completely inert and does not degrade. It never needs to be replaced. Regular cleaning (monthly rinsing) is sufficient to maintain its effectiveness by removing debris without affecting the internal bacteria.

Does Matrix eliminate nitrates?

Yes. Its macropores support denitrifying anaerobic bacteria that reduce nitrates.