Seachem MatrixCarbon

• Spherical bead shape – resists compacting and channelling the way granular carbon can, so water keeps moving through the whole bed rather than finding one easy path.
• Low ash content – Seachem states this minimises the carbon's own impact on pH, unlike cheaper carbons that can leach alkalinity.
• Removes organics, colour and odour – clears tannin tint, general odour and dissolved organics from the water column.
• Fresh and saltwater safe – one product across the whole store, no separate marine version.
• Treats water from 5c per litre on the largest pack – see Specifications below for every size.

Litres treated is calculated from Seachem's published dosing guide (250 mL treats 400 L for several months). It describes how much water the carbon is dosed against, not a guaranteed lifespan – actual replacement timing depends on bioload and flow, and Seachem does not publish a fixed number of months.

Match the pack to the water you're running carbon on, not the whole tank volume, if you only run it periodically. A nano tank or a quarantine setup rarely needs more than the 100 mL bottle; a single medium canister filter is usually well served by 250 mL or 500 mL; multi-tank fish rooms and large systems are where the 2 L and 4 L packs earn their lower per-litre cost.

Rinse the carbon before use to remove any dust from shipping, then place it where flow through the media is highest – a canister filter media basket, a dedicated reactor, a chemical filtration module, or a mesh bag in a box filter, sump or the high-flow section of a trickle filter.

Suitable for: fresh and saltwater tanks that need water polished – clearing tint, odour and dissolved organics – in canister filters, reactors, sumps and box filters with reasonable flow through the media.

Not suitable for: replacing biological or mechanical filtration – MatrixCarbon is a chemical filtration stage only, and won't process ammonia, nitrite or nitrate, or remove suspended particles. It will also adsorb some medications from the water column, so remove it before dosing a treatment course and don't run it again until the course is finished.

There's no fixed replacement calendar – Seachem's guidance is to watch for the signs the carbon is exhausted rather than count weeks. Replace when water discolouration, odour or general organic load starts to return, which is typically after several months of continuous use, sooner in heavily stocked or heavily fed systems.

• Seachem Tidal hang-on filters – MatrixCarbon fits neatly into the media basket of the Tidal 35 through 110 range for on-the-fly chemical filtration.
• A mechanical filter pad or floss ahead of the carbon, so debris doesn't foul the media before its chemical capacity is used up.

Ships as a standard parcel with no special handling required. Covered by the consumer guarantees under Australian Consumer Law in addition to Seachem's own product guarantee.

How long does a pack of MatrixCarbon actually last?

Seachem doesn't publish a fixed number of months – treat the "400 L per 250 mL" figure as a dosing guide, not a countdown, and replace when clarity, odour control or colour removal starts to fall away.

Can I use MatrixCarbon in a marine or reef tank?

Yes – Seachem states it's safe for both fresh and saltwater, including reef systems.

Does running carbon strip trace elements or medication from my tank?

It can adsorb some medications and organics from the water, which is exactly what it's designed to do for waste products. Remove it before starting a medication course and hold off running it again until the course is complete.

Which pack size is the best value?

The largest packs are the cheapest per litre treated – the 2 L and 4 L bottles both work out to around 5c per litre, against 13c per litre for the 100 mL bottle. Buy the size that matches how much carbon media you actually run, though, rather than the cheapest per-litre figure alone, since unused carbon doesn't keep working once it's exhausted.