The product consists of 50 pieces of simple and practical bio-filter balls, which have a plastic construction with a high performance cotton filling and are ideal for the oxygen supply of your water exchange and gas. Equipped with a mesh bag to store these organic balls. Easy to rinse and use, porous design, improve bacteria filtering effect, lightweight and easy to carry. The filter balls provide a large surface area for bacteria and thus achieve a very high level of efficiency for natural biological filtration. Sufficient quantity can meet your different needs. Aquarium Filter Bio Balls which are excellent for oxygenating your water and aiding the gas exchange process. A precious aid to restore the natural quality of the water and offer the most suitable living environment for fish. Ideal for everything freshwater or saltwater aquarium, or mini reef aquarium. As the water flows into the inner space, the time is increased by using the nitrifying bacteria to achieve the biochemical