Foodie Puppies Nano-Tech Bio-Media is made of ceramic beads and is completely inert. Adopted from the sewage treatment industry, the Nano-Tech Bio-Media uses a proprietary technology to form the inert ceramic beads into a manageable shape (spheres, blocks, plugs) for household aquariums. With an ultra-high surface cross-cutting ratio and filtration area, each Bio-Sphere has up to 54m² surface area (580ft²) and each Bio-Block has up to 1,080m² surface area (11,635ft²) for the establishment of bacterial colonies, which allows it to effectively control the quality and stability of the water column.