POU or POE - What's the difference, which do I need?

POU or POE - What's the difference, which do I need? - Cascadian Water

Gabe Ergler |

What do POU and POE mean?

POU and POE are acronyms for "Point Of Use" and "Point Of Entry" respectively. They describe where a water treatment system is used. A POE system treats higher flow rates than the POU system.

POU Water Treatment

POU treatment systems are small in size and are designed for low flow rates at a specific single location. For instance, a system designed to treat water at the kitchen sink, is considered a POU system. POU systems treat flow rates less than 5 gallons per minute. POU systems such as under counter RO (reverse osmosis) units produce only 20 to 50 gallons of water per 24-hour period.

Other common uses for POU treatment systems are

  • Appliance protection such as just in front of a tank-less or on demand hot water heater
  • Ice maker and refrigerator drinking water
  • Specialty filter pitchers kept in the refrigerator

POE Treatment

POE treatment systems are much larger in size compared to a POU system and are designed to treat higher flow rates. These systems are meant to treat all the water at the Point of Entry to the home or business.

Example POE systems

  • Water softeners
  • Water filters
  • Ultraviolet sterilizers

What Size Treatment System is Right for You?

The right system depends upon several factors

  • What problems need fixing
  • What flow rate is required
  • How much water needs to be treated
  • How much space is available
  • Do you want treated water everywhere?
  • What is the cost

Here is a table that summarizes the key differences between POU and POE systems:

Feature POU 
Cascadian POU Water Treatment System
Cascadian POE Water Treatment System
Size Smaller Larger
Treats Water at a single location All water entering the home
Best for Fixing specific problems, such as chlorine taste or odor Removing contaminants from all water entering the home
Flow rate Lower Higher
Space required Less More
Cost Lower Higher


A complete treatment system can have both POE and POU. Consider this scenario, You want to treat all the water in your home or business and you install a POE system. Perfect but, if your home or business has been plumbed with a soft water loop the cold water in your kitchen is not treated. If you want to treat kitchen cold water you would need to purchase a POU treatment system for the kitchen water.

Perhaps the best place to start your search for a POE or POU treatment system is by taking our Easy Filter Finder Quiz. Answer a few simple questions to find the best treatment for your needs.


Good To Know

What is a soft water loop and why I might need a POU system?

Why a POU filter is better than an under counter RO