System Reef-resh is an innovative method for true low-nutrient reef keeping. By harnessing the power of microbial activity, the system provides a natural and non-chemical solution to unwanted nutrients in home aquaria.Concentrated mixture of dormant bacteria. A custom blend of bacterial strains with concentrations of over 80 billion cells/ml. In their planktonic state, these bacteria serve as a highly nutritious food source for corals and zooplankton. More importantly, these complimentary bacterial strains form nutrient consuming biofilms.