Ceramic rings have long been used as a filter medium in domestic aquariums. Pores in the ceramic rings help and encourage the build-up of useful bacteria, which in turns converts harmful substances, like ammonia, to enhance the quality of the aquarium water. The ceramic rings can be used with all types of the filtration system and in conjugation with other filter mediums, like a sponge and activated carbons. (however activated Carbon may affect the potency of medicine and therefore while administering medicine, it is recommended to remove activated carbon to attain desired effect/impact of the medicine) It is a high-performance ceramic ring even in small quantity. Simultaneous breakdown of nitrites and reduction in nitrites. Healthy fishes and plants. No emission of harmful substances. Fewer water changes. Can be used in most filters-both fresh and saltwater. Long-lasting. This product is suitable in almost all filter, both in fresh and saltwater aquarium. Briefly rinse the bag holding the rings under running water (it is recommended to use aquarium water and not Tap water for this purpose). Place the ceramic rings inside the filter or under the gravel filtration system. Please note the formation of the useful bacteria is a long drawn process and patience is recommended. You could also add bacteria into the aquarium to expedite the process of nitrification.