ReeFlowers Bacteria Feeder contains various food sources that facilitate the rapid growth of the beneficial bacteria that helps to reduce the amount of nitrate and phosphate in fresh and saltwater aquariums. The bacteria biologically cleans the aquarium water providing a more natural environment for aquarium inhabitants. It is very effective at reducing the nitrate and phosphate levels in salt and freshwater aquaria. It is recommended that 2ml of ReeFlowers Bacteria Feeder is added for every 100 litersof water once every two days (for average loaded salt freshwater planted aquariums). Do not exceed 5ml in any one day and for long-term use no more than 2ml should be used on a daily basis.