Casco Pure is a new media similar to Bacto Balls but it is designed for large aquariums and retail fish systems. Read more about it here:
http://aquanerd.com/2018/07/casco-pure-media-for-large-tanks-and-retail-shops.html
http://aquanerd.com/2018/07/casco-pure-media-for-large-tanks-and-retail-shops.html