Product contains a unique composition of freeze-dried probiotic bacteria and nourishment to facilitate their multiplication. Pro Bio F is especially recommended for small aquariums in which installing a filter with polymers is not possible or it is much more difficult. It can replace the administration of VSV or other carbon sources. The unique composition of specially selected strains of probiotic bacteria has been developed to accelerate the decomposition of organic matter. It improves clarity of water and promotes cleaning the substrate. The use of Pro Bio F reduces the amount of nitrate to an undetectable level, providing the coral with perfectly balanced living conditions and excellent colouring.