What Are Living Rocks?
Rocks themselves are not alive. But in a coral reef rock-like lime substance is continually produced from the skeletons of dead rock corals and the shells of mussels and other creatures which are bound together by sponges and calcareous algae. This soft, porous rock is inhabited by countless marine creatures and contains the most diverse range of useful bacteria.
Every piece of living rock is a veritable microcosmos in its own right. After placing such a rock in an aquarium without epibacteria-eating fish – i.e. in a Nano Cube, it will soon be possible to observe how the most diverse organisms develop on the rock. These may take the form of corals, sea squirts or magnificent decorative algae – and no-one knows beforehand what will grow there. As such, a piece of living rock from a coral reef is a never-ending source of unique surprises.
It is important for the rock to have been stored in healthy sea water for several weeks at the retail outlet, so as to ensure that there are no dying organisms such as sponges on its surface. Choose attractively shaped and porous pieces of rock.
Good reef rock does not look grey and "dead", but is covered in diverse organisms, e.g. pink-coloured lime red algae, green or red macro-algae, tube worms or small corals. Always place the rocks in the aquarium with the side covered in such organisms facing upwards.