Deep sand bed
The Deep Sand Bed (DSB) or deep sand bed method describes a method with which reef aquariums are operated. It was developed by American aquarists.
The basis is a near-natural, very high substrate made of very fine aragonite sand . The grain size should be 0.2 to 1.0 millimeters. In large public show aquariums, the substrate is up to 30 centimeters thick, in private aquariums you cannot achieve a thickness of more than 10 to 15 centimeters.
The thick substrate has a huge surface and offers nitrifying and denitrifying bacteria a settlement area and thus acts as a biological filter. In addition, it provides a habitat for a large and species-rich fauna of small invertebrates that are brought into the aquarium through live rock .
The aragonite sand slowly dissolves up to 50% in a period of 18 to 24 months and thus ensures a calcium enrichment of the water. Lime water and a calcium reactor are not necessary. Aragonite sand only has to be poured in after a while.
Other requirements of modern reef aquariums such as strong lighting using halogen spotlights (HQI), optionally combined with blue T5 or T8 lights, or pure lighting with modern T5 lights and strong water movement also apply to the Deep Sand Bed. The aquarium water should be completely circulated ten to twenty times an hour.
In contrast to the Jaubert system , which also works with a high, but coarse-grained substrate, animals such as gobies , crabs or sea cucumbers digging and turning the substrate are desirable for the Deep Sand Bed .
It has been shown that in reef aquariums operated with the Deep Sand Bed method, even large polyp hard corals , which grow very slowly in other reef aquariums, can become very large, and that even "higher plants" such as seaweed , whose maintenance was previously impossible, thrive. Another advantage is that a lot of light is reflected by the brilliant white aragonite sand, so that the corals also receive light from below and the loss of tissue in the shaded, lower area of the corals is avoided.
Other systems for reef aquariums are the Berlin system , the already mentioned Jaubert system and the mud filter system .