How the Aqualim Shower Head Works

A 10-minute shower might seem like nothing on a cold, dark morning.
A 10-minute shower might seem like nothing on a cold, dark morning.

In an age of droughts, water shortages and intensified eco-awareness, long, luxuriant showers are a thing of the past, right? In fact, lots of people still take long showers, especially considering that in terms of water usage, 10 minutes is pretty long.

In the developed world, water doesn't cost all that much money. The water for a daily, 10-minute shower only runs about $20 a year in the United States [source: NCCES]. The electricity to heat it costs about $60 to $80 a year-- not a huge chunk of an electric bill [source: NCCES]. But a daily, 10-minute shower does cost a whole lot of precious, life-sustaining, crop-watering H2O.

A regular showerhead uses about 5 gallons (­­­19 liters) of water per minute, so a 10-minute shower uses 50 gallons (190 liters) of water [source: NCCES]. That's a bathtub's worth of water. Switch to a standard low-flow, water-saving showerhead, and you're down to about 2.5 gallons per minute, or 25 gallons for that 10-minute shower [source: NCCES]. That's still using more water in a single shower than many families in rural Africa consume in a whole day [source: CCF].

The problem is, shampooing, conditioning and soaping up takes time (especially if you have long, thick hair). Add in any additional shower treatments, like steam-activated cleansing masks, medicated shampoos that have to sit, or a thorough loofah scrub, and 10 minutes seems like a positively quick shower. Twenty minutes under the water is far from unheard of (especially at 6 a.m. on a cold morning). It passes faster than many of us realize.

So, how do you reduce a 100-gallon shower routine to one that uses 25 gallons, or even just 15 gallons? Awareness goes a long way. So does inconvenience.

In this article, we'll look at an invention called Aqualim (as in, "water limiter"). It's a showerhead attachment that incorporates awareness and inconvenience into a device the inventor says successfully cut his teenage daughters' shower time in half.

While there are a bunch of shower-monitoring devices out there, Aqualim takes a different approach to the problem.

The Aqualim: Tracking Volume, Not Time

It's easy enough to use a stopwatch to time a shower, or set an alarm to go off after your allotted shower time. But devices that measure time aren't the most exact way to monitor water use, because different showerheads use different amounts of water. Depending on the water efficiency of your chosen spout, your shower might use anywhere from 1 gallon to 7 gallons (4 to 26 liters) of water per minute [source: FYP].

If your goal is to limit your water consumption, and not just your shower time, it's helpful to monitor your actual water consumption. That's what Aqualim does: It monitors volume, not time.

Aqualim is an attachment, not an actual showerhead. You screw it into the pipe your shower water flows from, and then screw your showerhead onto Aqualim. The attachment is preset to limit your shower to a certain number of liters. In the Aqualim prototype, the amount is 40 liters (11 gallons), which gets you about five minutes with a water-conserving showerhead (that amount could change if or when the device comes to market).

The unit counts volume using a hydraulic motor. As water flows through the Aqualim, it spins a motor. The motor runs a liter counter. When the counter nears 40 liters, water pressure decreases. That's the "warning mode." When the counter reaches 40, the device cuts water flow down to a dribble.

That's not the end of the story, though -- if you're still soapy, you can resume your shower by turning off the water faucets and then turning them back on. That resets the counter, and the process starts all over again.

This feature, while certainly handy, begs the question: If you can just turn the shower right back on, how does it reduce water consumption?

Saving Water

By adding an attachment that measures water flow to your showerhead, you become conscious of your usage.
By adding an attachment that measures water flow to your showerhead, you become conscious of your usage.
Photo courtesy of U.S. Government Blog

Chances are good that if you find yourself standing in the shower for 20 minutes, you're not thinking much about the time. You're probably thinking about how good the steaming-hot water feels. Aqualim puts a stop to that -- or at least interrupts it.

The basic idea is twofold: First, to make bathers more aware of how much water they're using, while they're using it. Presumably, someone who installs an Aqualim cares about water conservation, so simply being alerted to each 11-gallon (40-liter) increment will have an effect.

The other part is simple annoyance: Each time users want to extend their water usage, they have to stand there cold for a few seconds, turning the faucets off and on. It's kind of like having someone walk into the bathroom every five minutes and yell, "GET OUT!" You can stay in there if you want, but it's probably worthwhile to hurry up and finish showering before you get yelled at.

At the very least, you'll be willing to go out and buy yourself a more efficient showerhead so you can get a few more minutes before the yelling starts.

According to Aqualim's Australian inventor, his teenaged daughters were using three or four cycles when he first installed the unit. They eventually got their shower time down to just one or two cycles [source: Daily]. Even if Aqualim inspired a 10-minute instead of a 15-minute shower, that's a savings of anywhere from 5 to 35 gallons (19 to 130 liters) of water a day, or up to 12,775 gallons (48,000 liters) of water per year. That's enough to fill a small residential swimming pool [source: ASI].

In March 2009, Aqualim won ABC Australia's New Inventors Award, which could help the inventors get a manufacturing deal. While you wait, you could pick up the Shower Manager, which reduces water flow after a certain preset time period. Or the "It Makes Sense Shower Head," which has a pull-chain that controls water pressure so it's basically an on-demand shower system. There's also the Waitek Shower Monitor available in Australia, which attaches to a showerhead to track water temperature and shower time and starts beeping when the water's been on for 8 minutes. It keeps on beeping until you turn the water off and then resets after a few minutes. If you turn the water back on before the reset, it'll just start beeping again.

Now there's a way to take the joy out of showering.

For more information on Aqualim, showering and water conservation, look over the links on the next page.

Related HowStuffWorks Articles


  • Aqualim.
  • "Aqualim." New Inventors. ABC.
  • Garry, Mike. "TV judges shower praise." Sunshine Coast Daily Online. March 19, 2009.
  • "Patent-pending Shower Head Could Save Millions Of Gallons Of Water A Day For Hard Hit Drought Regions." 1888 Press Release. March 14, 2008.
  • "Saving Water and Saving Energy." North Carolina Cooperative Extension Service.
  • "Shower monitor cuts water bills." PR-inside. Oct. 31, 2006.
  • Sundstrom, Kathy. "Turning off the taps." Sunshine Coast Daily Online. Dec. 7, 2007.