How to Select a Filter Cartridge for Whole House Sediment Removal
Cartridge filters have the advantages of being low-cost, easy to install, using no electricity, and generating no wastewater.
However, the disadvantage of cartridge filters is that eventually, sediment will plug up the Water Filter Cartridge membrane's pores, causing a pressure drop and resulting in a loss of water pressure in the home or business.
Cartridge filters, however, are easy to change and, in the case of some pleated cartridges, are easy to clean and reuse.
Cartridge filters for sediment removal come in many sizes and types, but they generally fall into two categories: Surface Filter Cartridges and Depth Filter Cartridges.
Cartridge filters are often installed in series with a larger micron-rated cartridge filter first, followed by smaller micron-rated filters down to 1 micron.
Surface Filter (Pleated) Cartridges
Filtration with surface filters takes place only on the surface of the filter membrane.
Sheets of polypropylene, nylon, or Teflon, etc., are pleated and bonded on ends to provide a high filtration area. The contaminants are trapped on the sheet's surface, forming a layer that will eventually aid filtration in itself.
As the pressure drop increases, the filter cartridge can be removed from the filter housing and washed off eventually.
One advantage of surface filters is they can be washed off, and the cartridge can be reused.
While pleated filters are often used as coarse pre-filters, usually in the range of 30 – 500 microns, they can also be used in sub-micron applications. Due to their definable pore size and structure, pleated filters provide finer and more consistent filtration.
Filtration ratings for pleated surface filter cartridges can be anywhere from 50 microns down to 0.04 microns absolute, and they are generally used in semiconductors or pharmaceutical water filtration.
A surface (pleated) filter has a much higher filtration area than a depth filter to compensate for the absence of depth. Filtration areas can reach as high as 11 square feet in a regular 10″ x 2.5″ cartridge or higher.
Depth Filter Cartridges
Depth filters are commonly seen as wound string, spun, or “melt-blown” cartridges that trap particles of larger size on the surface and smaller particles under the surface down to the center core.
They work best when a variety of particle sizes are being filtered. Depth filters remove more sediment and hold more sediment overall without losing pressure than a surface filter cartridge.
How Small is A Micron?
Filter cartridges for sediment removal are rated in microns. A micron rating for a water filter indicates the ability of the filter to remove contaminants by the size of the particles.
A marked “5 microns” filter has some capability to capture particles as small as 5 microns.
Filter micron ratings for water are usually Nominal or Absolute.
For sediment removal, nominal-rated cartridges are more common.
An absolute rating of 1 micron is essential for removing Giardia, a type of parasite, making it crucial that the filter cartridge meets this specification.
A. Nominal Micron Rating
NMR usually means the filter can capture a given percentage of particles of the stated size. For example, a filter might have a nominal rating of 90% at 10 microns.
B. Absolute Micron Rating
Absolute Micron Rating or “AMR” is a single-pass test obtained by passing fluid-containing glass beads through a flat sheet of filter material. Any beads that pass through are captured and measured. You want an AMR filter for removing parasites and cysts if you are filtering lake or creek (“surface water” or your well water is under the influence of surface water
Which Type of Filter Cartridge is Best?
One advantage of whole-house filter housings is that you can experiment with different water filter cartridges to see what works best for your application.
Generally, we recommend pleated 50-micron filter cartridges followed by a dual grade 25/1 micron depth filter.
For very fine sediment in the range of 1 to 5 microns, we recommend dual-grade depth filters.
Dual-grade depth filters start at 50 on the outside and filter down to 5 microns on the inside, which is very effective over a wide range of sediment particles.
Dual-grade filter cartridges remove 2.3 times the amount of sediment that standard spun or string-wound filters remove.
For more information on removing sediment from your water, visit our Sediments page on our Water Problems tab.
If you still have questions, don’t hesitate to e-mail us at support@cleanwaterstore.com, leave us a message on Facebook, or use our online contact form for prompt, personalized assistance from our trained professionals. Thanks for reading!
