HTH 67035 D.E. Filter Aid, 10 LBSThis D. E. Filter Aid is diatomaceous earth, a filter media that will trap particles as much as 20 times smaller than sand or cartridge filters. Highlights: D. E. filter aid Removes particles as small as 2 6 microns Replacing this media as needed helps ensure optimum performance from your filter to keep your pool water clear For use in all D. E. (diatomaceous earth) filters on pools and spas Great for all D. E. filters on pools and spas and is