Non-living (geochemical) Matrix

Typical geochemical matrices in TROPICAL Live Rock

Skeleton of stony coral

Skeleton of Aquacultured Acropora sp.

Skeleton of Aquacultured Acropora sp.

Non-living matrices or substrates communly used in
Aquacultured Live Rock

Mined lime stone
Mixture of cement and calcareous media
ecoLiveRocks substrate (learn more)
The non-living or geochemical matrix is the inert portion of Live Rock. It plays an essential role as substrate is needed by bacteria and other cryptic organisms that require a hard surface for support. Also, when the non-living or geochemical matrix is made of calcium carbonate, it also plays a key role in the carbonate cycle, balancing alkalinity and buffering pH.

The geochemical matrix can be formed by geological or biochemical processes depending on the region of formation. In the tropical ocean near coral reefs, most Live Rock is made of skeletons of stony corals. These skeletons are made by coral-mediated deposition of calcium carbonate. When corals die, their skeletons get exposed and become substrate that can be colonized by encrusting and cryptic organisms.

In temperate oceans and in regions away from coral reefs (which is vast majority of the ocean), substrate is made of granite, basalt and other rocks created by geological processes. However, even in temperate oceans there are many organisms that have calcium carbonate skeletons. Therefore some rocks that start from non-calcareous substrates can be colonized by barnacles, oysters, coralline algae, etc. and eventually may yield a calcium-rich Live Rock.
Geochemical matrix typical of TEMPERATE regions


It is very important to use Live Rock grown in conditions similar to the tank conditions where it will be used. Use tropical Live Rock in tropical tanks, and use temperate Live Rock for temperate (cold) aquariums.

Pretty much anything you put in the ocean will get colonized by encrusting organisms, effectively turning substrate into Live Rock. This fact has been exploited by aquaculture farms of Live Rock, where different mined or man-made substrates are used as the non-living matrix and foundation of Live Rock (see examples on the right).

This is an old piece of a wine glass
that fell in the ocean and got colonized by
coralline algae. The non-living matrix in this
"Live Glass" is of anthropogenic origin.