low flow fixtures aerator

Low Flow Fixtures 101: or How to Save 11,000 Gallons of Water in 5 Minutes


In our post last week, Four Principles of a Clean, Green Bathroom Update, we listed water conservation as the number one priority and threw around the term “low flow fixtures” without really investigating it.  We DON’T mean  you need to limit yourself to an uncomfortable trickle of shower water two mornings a week.

Modern plumbing fixtures  have come a long way on water saving measures and you can make a significant dent in your water usage by a few simple changes and updates without affecting your quality of life one bit.  The key component to low flow faucets (sink or shower) is the aerator attachment.  While you may want to update your whole bathroom, or just your whole faucet, you can actually get an amazing water saving result by simply switching out the aerators and shower heads in your bathroom for low flow models in a five minute DIY procedure.  Here’s how!

What is an Aerator?

What does it SOUND like it is?  An aerator is a small mesh circle attached to the end of your sink faucet which mixes th water with air by forcing the water to separate in to many tiny streams rather than coming out in a unified rush, as from a garden hose. This reduces splashing and the force of the water from the tap making it more useful for activities like filling a glass or hand washing.

There are actually three types of faucet end aerators (as per this graphic by plumbingsupply.com).  Standard aerated flow is used for household applications (like your bathroom faucet).  Spray aerators separate the water more completely into multiple streams (resulting in even less splashing) and are generally specified for public handwash sinks in restrooms.  Laminar flow devices prevent separation of the water – often used to ensure extra sterile water for healthcare facilities.

aerator types

Traditional aerators simply pass the water through a screen to mix in water and do not restrict the rate of flow of the water at all and result in 2.2 gpm (or gallons per minute).

Take a moment to contemplate two gallons per minute down your drain.  It seems like a lot of precious potable water to be using to rinse off a toothbrush doesn’t it.

Water saving, low flow aerators generally have a flow of 1.5 gpm and some reduce flow to 1 gpm for a savings of more than 50%.  You probably won’t even notice the difference and you’ll have saved half your bathroom sink water use without even remembering to turn off  the faucet while you brush!

Low flow Shower Heads

Shower heads are a little more complex than faucets since people have a lot of preferences regarding how they like to be hosed down in the morning.  But whether you like needle sharp spray to wake right up or a soothing rain style downpour you can still have a water saving experience.

Prior to water conservation measures, standard shower heads delivered 6-7 gpm at a water pressure of about 80 psi (pounds per square inch).  Low flow heads can simply restrict that flow by using a more stringent aerating screen or a flow restrictor (a disk with a circle punched in it to reduce the amount of water able to pass through the head) or they may have more complex mechanics designed to compensate for reduced flow and maintain that standard 80 psi of pressure.  To be considered “low flow” today, a shower head should reduce flow to 2.5 gpm.

Note: Shower heads that DON’T match standard pressure expectations tend to give water conservation a bad rap (and are often sabotaged by home owners to return them to standard flow).  We recommend paying attention to pressure since our goal is to help you save water not to make you miserable.

So how do you know what product to buy?  

The easiest way to know you’re getting a water saving fixture is to look for the WaterSense label on the packaging.  WaterSense is an EPA run program which certifies that a product:

  • performs as  well or better than less efficient counterparts (i.e. you won’t lose out on quality)
  • is 20% more efficient than industry average (its not just a greenwash)
  • is independently certified by a third party (the manufacturer doesn’t get to self-identify as green)

WaterSense certifies toilets, urinals, bathroom sink faucets, shower heads and new homes.

Upgrading your Bathroom Faucet, or Saving the world, one faucet at a time

Getting back to that dramatic claim in the post title: The EPA website states that “twisting on a WaterSense labeled aerator … can save a household 11,000 gallons of water over the life of [one] faucet.”

Now that you understand how water saving aerators work are you ready to  make a change in your life?  It’s literally as easy as one, two, three**.  You may not even require any tools.

The aerator on a bathroom faucet is encased in a little metal housing which can be un-screwed from the actual faucet unit for easy replacement.  So simply:

1. Unscrew the housing from the faucet and pop out the existing aerator and washer.

2. Replace the old aerator with a WaterSense certified one and pop the washer back on.

3.  Screw it all back into place.  Finger tight will do.

** If your predecessor went overboard with the tightening you may need a wrench to get the housing un-screwed.  You can replace the original rubber washer but most aerators come with a new one that you can switch out – some even come with a new housing too.  If you have any trouble with the screwing and un-screwing you may want to clean out the threads on the housing or faucet.  But at its most basic this is a tool-free job that shouldn’t take more than a minute or two.

To make sure you’re getting the right type and size of aerator you may want to bring the old one along with you to the hardware store.  The replacement may cost as little as two dollars.

This video by master plumber Ed Del Grande for Kolher’s Save Water campaign demonstrates just how easy the process should be.

Upgrading your Shower Head to Low Flow

Replacing an older model shower head is very nearly as easy.  In that case you’ll unscrew the entire shower head from the wall mouted pipe and replace it with a new low flow model.  For that little home improvement task you’ll probably need two wrenches (to get the un-screwing process started) and some teflon tape to wrap around the threads of the screwed attachment before you pop on the new one. There are a host of youtube videos (here’s just one) demonstrating the process, none over five minutes long.