BioPearls ensure crystal-clear and biologically perfect water quality. Thanks to their size and round design, they enable much finer filtration, even of the smallest dirt particles such as organic substances. In addition, the BioPearls are of purely natural origin. They therefore offer an environmentally friendly alternative to conventional plastic filter media. The material is also very durable. The 250 ml packaging size is perfect for filling small biological filter chambers, such as internal filters.