Fiber Clear FCR-048B Filter Media; 3 lb, 12/Case. Fiber Clear is a natural cellulose fiber filtration media that replaces DE in all swimming pool and spa filters. It is also an excellent topcoat for sand filters, and an effective precoat for cartridge filters. Fiber Clear provides ultra-fine filtration to two microns, superior to DE. It covers the grids efficiently and completely, backwashes 99+ % out of the filter, is biodegradable, non-toxic, and will not clog drains or sewers. The use of Fiber Clear in conjunction with an approved biocide and sanitized provides the clearest, cleanest, and safest pool water possible. Water clarity will be noticeably improved!