Why would I need a prefilter on my water treatment system?

Quick-change filters remove contaminants as small as 0.5-micron by mechanical means (see individual system specification sheets for performance claims and FIFRA registration information). Microns are extremely tiny, in fact, human hair has a width of 40 microns. This means all filters we carry are very effective at removing many contaminants. However, if your water is particularly dirty, we recommend placing a pre-filter in front of your system. Pre-filters are typically 10 to 25 microns, allowing them to remove the larger particles that might prematurely plug your system. Many of our systems offer a pre-filter option.

Why Do Some Water Systems Use Pre-Filters?

There are two primary reasons to use pre-filters. The first, and typically most important, is that pre-filters protect the primary filtration media from damage and degradation. Some types of filtration media are susceptible to damage from certain types of contaminants such as chlorine or bacteria. A pre-filter can be installed that is designed to remove those damaging contaminants so that they cannot affect the primary filtration media. In other situations, the pre-filter is used simply to remove some of the larger and easier-to-catch contaminants so that they don’t clog up the primary filter, which extends the primary filter media’s life.

The second reason pre-filters are used is to remove contaminants that the primary filter is unable to catch. This allows the water system as a whole to remove a wider range of contaminants and produce better quality water than you would get by using the primary filter on its own.

What are some common water systems with pre-filters?

Water softeners: Chlorine can be very damaging to the resin beds inside of water softeners, which is why many water softeners will use a carbon pre-filter to remove chlorine before the water is softened. Some water softeners, such as the Hague WaterMax, include a sediment pre-filter to protect the system from large suspended particles.

Reverse osmosis systems: Reverse osmosis (RO) can remove almost every type of contaminant that you can find in water, so why would it need a pre-filter? A pre-filter like a carbon filter can remove the larger suspended and dissolved particles from the water before the water reaches the RO membrane, which extends the life of the media. By letting the RO membrane only worry about the smallest contaminants, the media will last much longer because its pores won’t clog as quickly. Many reverse osmosis systems also have a UV lamp pre-filter to take care of bacteria before it reaches the RO membrane.