Pentair FNS Plus D.E. Filter

Filtering with diatomaceous earth (D.E.) gives you water that really sparkles. That’s because D.E. filters remove the tiniest of contaminants particles as small as 5 microns (an average grain of sand is 1,000 microns!). Even though these particles can’t be seen individually, collectively they greatly affect water clarity.  Here’s why diatomaceous earth filters work so well. Water passes through a series of D.E. coated grids. Under a microscope, D.E. looks like a collection of tiny sponges. And just like a sponge, water can pass through, but microscopic impurities like dirt, algae and some forms of bacteria can’t.