Seachem Matrix Carbon 250 ml

Seachem MatrixCarbon is a high-efficiency spherical carbon with low ash content, minimal pH impact, and the lowest leachable phosphate on the market.

• High efficiency spherical carbon.
• Very little impact on pH due to low ash content.
• Lowest leachable phosphate level on market.
• High removal capacity; large surface area.

MatrixCarbon is a truly unique activated carbon. It is formed as a spherical bead for optimum hydrodynamics, and will not pack. It permits maximum water flow and contact with its high density of macroporous binding sites. MatrixCarbon has a very low ash content as indicated by its minimal impact on pH. Even when added to distilled water, it does not raise pH above 7.0. While all carbons contain phosphate, regardless of false claims to the contrary, MatrixCarbon has the lowest detectable leachable phosphate content of all major carbon brands tested. MatrixCarbon outperforms other high grade carbons by at least two-fold when compared for total capacity to remove aquarium organic matter, rate of adsorption, and duration of use.

While carbon is generally considered to be a chemical filter, that is not precisely true. It is in fact a mechanical filter as well, but it is only capable of mechanically filtering objects of molecular size. It functions through extremely small cracks and crevices, called macropores and micropores. Microporous carbons remove primarily metals and smaller ions (like trace minerals) and are best suited to air filtration, while macroporous carbons remove primarily larger organic molecules (like nitrogenous waste) and are best suited to water filtration.

The ingredients from which a carbon is manufactured determine whether it will be macro- or microporous. Carbons made from coconut shell and other organic products form microporous carbons, while carbons made from bituminous coal form macroporous carbons. MatrixCarbon is a bituminous coal-based, macroporous carbon. It is the only spherical carbon on the market, allowing for maximum water flow. It is sized to allow full penetration by water, but not small enough to escape filter bags. All carbons contain phosphate. However, that phosphate DOES NOT come from washing the carbon with phosphoric acid. Most carbons are washed with sulfuric acid. The phosphate is contained in the ash from the carbon source. The main purpose of acid-washing is to remove ash. Because of MatrixCarbon’s hydrodynamic properties, more ash is washed from our carbon than any other. Therefore, it has the lowest leachable phosphate on the market.

The Seachem Matrix Carbon 250 ml is a biological media, giving nitrifying bacteria surface area to colonize — see our guide to choosing filter media for how it fits alongside mechanical and chemical stages.

Specifications

A spherical macroporous activated carbon. The shape keeps flow through the bed high while holding water in contact with the adsorptive surface.

Capacity: 250 mL treats about 400 L (100 US gallons).

Typical service life: three to six months in a clean tank; hours in badly fouled water.

Like every activated carbon it contains some phosphate, though Seachem rate this one lowest for leachable phosphate — worth knowing in a planted or reef tank.

Setup & Use

Bag it, rinse it, and put it where water is driven through it at speed — a canister basket, a chemical filtration module, a box filter or the high-flow part of a trickle filter.

Remove it before dosing any medication, and put fresh carbon back afterwards to strip the residue out.

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.