Substrate is a necessity for any aquarium ecosystem. Generally, it is recommended to have 1-2 inches of substrate in any aquarium, however this is all dependent upon the population of the tank. Substrate provides a minuscule but efficient natural filter.
The marine aquarium hobbyist is faced with a wide variety of substrates to be used in the aquarium. Trying to decide what to use is usually based on aesthetics and function. In the past, the options were dolomite (calcium-magnesium-carbonate) rock or crushed sea shells/coral.
There are many different substrates to choose from when setting up an aquarium. For freshwater there is gravel, fluorite, and cichlid sand. For saltwater tanks the best substrates are aragamax sand, live sand, and dolomite. Choosing the right one depends on what type of setup and fish in the aquarium.
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