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

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

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

So which do you need?

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

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 Filter Finder Quiz. Answer a few simple questions to find the best treatment for your needs.


A water treatment professional will be able to help you with a comprehensive treatment plan.

Good To Know

What is a soft water loop?

Why a POU filter is better than an under counter RO

More about Cascadian POU treatment systems

Find your filter fit

Use our short product quiz to find our best fit treatment for your personal needs.

Filter Finder Quiz