Gear Review: CamelBak Flow Meter

Hydration reservoirs and bite valves make it easier for hikers and athletes to stay hydrated during exercise. But one of the biggest complaints that people have about them is that you can’t see how much water you have left in your backpack without taking it off. This compromises the purpose and convenience of carrying a hydration system because people don’t drink enough when they’re afraid of running out.

To address this problem, CamelBak has introduced a clever new device called a Flow Meter that measures how much water you have left and your rate of consumption. It takes the guesswork out of staying hydrated while exercising and provides the opportunity for anyone to assess his or her fluid replacement needs.

Trail runners, mountain bikers, and hikers can all benefit from the Flow Meter.

How it works

The CamelBak Flow Meter consists of a digital computer and a flow sensor that is inserted into, or comes as part of, your hydration tube. The flow sensor looks like a miniature generator turbine. It spins as you suck water past it, letting the Flow Meter determine how much water you’ve consumed.

The ends of the flow sensor are barbed and should form a watertight seal, as long as they fit snugly with your hydration hosing. Once attached, the Flow Meter snaps into the Flow Sensor and records your usage data.

You can buy the Flow Meter separately and splice it into the drinking tube of an existing hydration system, two to eight inches from the bite valve, or get one that is pre-installed with the CamelBak Omega Deluxe 70 oz. Hydration Reservoir, no assembly required.

Using the Flow Meter

Programming the Flow Meter is easy, but you need to carefully read the directions first. Due to space limitations on the digital meter display, CamelBak uses two and three letter function (AC, ET, AG, TV, PHG) and unit (KG, OZ) abbreviations to label the different metrics tracked. While the function abbreviations may not be immediately intuitive, they are easy to remember once you start to use the Flow Meter.

The Flow Meter has two limitations to consider before users buy and install a unit onto their existing hydration set-ups. First, CamelBak advises against using it with non-water fluids. If you choose to use it with sports drinks, the company recommends you thoroughly clean the system after every use.

Second, with an operating range of 35° to 122°F (2° to 50°C), it is not designed for use at or below freezing temperatures. So, don't buy one for winter outings. The Flow Meter is designed for three-season activities, preferably with drinking water.

Simplest-use scenario

Basic setup requires that you enter a fluid unit of measure (ounces or liters) and the total volume (TV) of water added to your hydration bladder. For accuracy, be sure to add the exact volume of fluid added, not the total capacity of your reservoir.

If that’s all the information you specify, the Flow Meter will measure and display the amount consumed (AC) as you drink from your hydration hose and the amount remaining out of the total volume (AR/TV).

Advanced programming

Meter with personal hydration goal
PHG stands for Personal Hydration Goal.

More advanced options are available that help you estimate how much water you need to consume per hour, track your consumption rate, and estimate when you will run out of water (ETE = estimated time to empty).

The personal hydration goal (PHG) is a computer-generated value that provides a suggested hourly consumption rate to help you stay hydrated during exercise. PHG may differ by individual based on type of activity, age, weight, elevation, temperature, humidity, medical conditions, and so on, but this provides a good baseline for estimating one’s hydration needs.

For example, when I entered my body weight (195 lbs), the Flow Meter calculated my PHG to be 24 ounces an hour. This is pretty close to my actual rate of water consumption per hour on strenuous day hikes and backpacking trips in moderate temperatures and humidity. I’d probably increase it to 32 ounces for hot summer days though.

Hydration system compatibility

If you buy the standalone version of the Flow Meter and try to integrate it with a hydration hose from another manufacturer, there is a good chance that they won’t be compatible.

For example, I tried to push the hydration hose of a Platypus hydration reservoir onto the flow sensor barbs, without success. The Platypus hose width is not large enough to fit, no matter how hard you push.

While CamelBak says that the Flow Meter is compatible with its own hydration hoses, installing the Flow Meter on one is still a struggle. Plus, once you get it on, you won’t be able to twist it off without cutting the hose lengthwise to remove it. It’s a really tight fit.

Given the hassle of cutting and splicing tubing to install a standalone Flow Meter, you should seriously consider purchasing the version where it comes pre-installed on a CamelBak Omega Deluxe 70 oz. Hydration Reservoir. A 100-ounce version of the system is also available.


When I was given the CamelBak Flow Meter to evaluate, I was skeptical about its utility. But after testing it, I found it useful for monitoring my water consumption and hydration rate on strenuous hikes in the mountains.

The Flow Meter is clearly useful for competitive endurance athletes such as runners and cyclists who need to carefully monitor their hydration rates. In addition, it is beneficial for recreational users who need assistance in calculating their baseline water consumption rate and monitoring their fluid replacement uptake.

However, I think you need to be a pretty serious athlete to pay the extra $30 for this device. Most of us have enough sense to drink when we’re thirsty, without the need for a hydration system attachment like the Flow Meter.

Product Specifications

Flow Meter thumbFlow Meter

  • Weight: 0.9 ounces (meter, sensor, and battery)
  • Dimensions: 2.5 x 1 inches (meter); 1.25 inches long (sensor)
  • Fluid Sensor and Digital Computer
  • Display and CR2032 Lithium Battery
  • Installation and operating instructions
  • MSRP: $30

Omega 70 oz reservoir with flow meter Omega Deluxe Reservoir with Flow Meter, 70 oz

  • Omega Deluxe Reservoir with HydroGuard Antimicrobial
  • Flow Meter
  • Quick disconnect with auto-shutoff
  • Ergo HydroLock Valve
  • MSRP: $58


CamleBak Flow Meter user reviews and info

Filed under: Gear Reviews

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CamelBak  |  Hydration Accessories


0 reviewer rep
108 forum posts
February 19, 2010 at 8:37 a.m. (EST)

Hi Phillip -

Good read and seems it would come in handy for sure - though now more batteries to worry about.

Question: Did they say an approximate length of time the batteries would last?

Lastly a helpful hint - To get the flow meter on a tube more easily simply take a cup of water - nuke it to boiling point - stick the end of the tube you wish to add the flow meter to in it for about 30 seconds to heat the hose up - the Flow meter barbs will slip on very easily. If the tube is too small or thicker you can try heating it longer. If, of course the hose is too small it'll be tougher to work it on, though it can be done. One would have to use their best judgment in the size of hose department as to whether it's too small to work. You don't want to force it on of course.

You can also use an adaptor with a small piece of hose between the flow meter and your normal hose - my not look the prettiest but will work. You can get the small barb adaptors at the local hardware store - most carry them for various size water lines in both brass and plastic/nylon etc.

- The heating hose technique works nicely for most all rubber hoses no matter what you're trying to put it on that has a barb and makes for attaching it much easier. Getting it off - well that's another issue and as you stated - probably has to be cut off lengthwise.

anyway - hope my two cents helps a little.

Nice read - It would be nice to see a solar one come out. If the little solar panel can power a calculater - should have no problems powering this - with battery back up of couse.

- Oh and a lcd back light would be nice for night hicking... or led screen... a blue tooth link to your head set with audio letting you know when your water gets low or your not consuming enough per hour... of course this added to the gps tracking link up letting me know how far i traveled per liter with silent mode interuption for the included wireless /bluetooth 8gb mp3 player it could have.

and to think it all started with a simple flow meter or am i wishing or inventing too much for such a small device? lol

hmmm... wonder if i'll get a royalty check or credit if they add any of those features? ;0)

130 reviewer rep
130 forum posts
February 19, 2010 at 9:39 p.m. (EST)

Great tips on heating the tubing to get it to fit over the barbs. I'll have to try that sometime. Camelbak does not estimate battery life, but I've had both of my flow meters for a few months now and they're still going strong. Part of that is due to an automatic power saving mechanism which puts the computer into sleep mode after 24 hours on non-use. Thanks for the comment!

Jim S
37 reviewer rep
749 forum posts
February 20, 2010 at 12:36 p.m. (EST)

I have to admit that at first glance my reaction was "huh", what the...

Where the innovations are probably useful and certainly will make someone some money, I have to wonder "what next?" How about an hour meter on a pair of boots? Maybe a built in weight scale on a pack? I'm thinking that a digital spoon would surely come in handy for something, like letting me know how close I am to the bottom of my instant oatmeal. perhaps long underwear with multiple temperature probes? All of this gear would report through wireless to a single wrist display, perhaps on the screen of my GPS, or better - to my sun glasses?

I turned on my GPS near a hydro-electric power station this week and it burned out the radio. So maybe a built in field sensor would be good and it would shut down all of the electronics gear when you entered an area of strong radio noise.

Is this flow meter guaranteed to work near power plants? If not will they replace it if it smokes? I haven't spoken to Garmin about my GPS yet, I'll let you know after I speak at them.


P.S. what ever happened to using a seashell for a spoon?

P.P.S. I suppose different manufacturers would use different systems so you would have have all compatible gear...

0 reviewer rep
415 forum posts
February 21, 2010 at 11:18 a.m. (EST)

Looks to me like the Flow Meter is essentially an altimeter for your hydration bladder, with the issue altimeters share: you have to calibrate them first to get accurate readings later on.

I've never bought an altimeter because I rarely found myself in a situation where the need to know my altitude outweighed the futz factor of recalibrating it before I started out.

Of course we can live without knowing our altitude; we can't live without water.

I do find it interesting that the one major complaint about water bladders -- you can't see how much you've got left -- seems like not such a big deal when a company actually puts out a product designed specifically to address that complaint.

I've seen a lot of skeptical responses to the Flow Meter, with a common perception that if you're athletic enough to need this level of accuracy on your water intake, you already know the information the meter provides.

One factor in the Flow Meter's behalf is the tendency to underestimate how much water you need if the weather changes or you're in an unfamiliar locale with significant differences in climate. I've run my bladder dry on the first hot hike of the season enough times to know better.

130 reviewer rep
130 forum posts
February 21, 2010 at 12:52 p.m. (EST)

Tom - I like your altimeter analogy. Spot on.

Alicia MacLeay (Alicia)
848 reviewer rep
3,902 forum posts
February 22, 2010 at 9:42 a.m. (EST)

I do find it interesting that the one major complaint about water bladders -- you can't see how much you've got left -- seems like not such a big deal when a company actually puts out a product designed specifically to address that complaint.

I agree. It's an interesting point.

I'll probably never use a Flow Meter for hiking and backpacking, despite being a type A person who tracks mileage and all sorts of other numbers (Besides, I gave mine to Philip for this review!).

I find the device interesting though and can see it being very useful for endurance athletes and racers -- trail runners and mountain and road cyclists -- to do number crunching and know how much water to carry for a race or training run down to the ounce.

It might be enlightening to use one occasionally to get a gauge on how much water you typically use in certain conditions. I tend to be overprepared in some areas, like carrying extra water for me and my kids. So, it could help me reduce that a bit and lighten my load.

Bill S
4,419 reviewer rep
6,010 forum posts
February 22, 2010 at 12:12 p.m. (EST)

Actually, this is not the first flow meter to measure and pace your fluid intake. A few years ago, there was a person associated with JetBoil who came up with a water bottle with a flow meter on it. You programmed it according to a table that took account of your weight, exercise category, and some humidity and temperature considerations. The guy was really enthusiastic about its benefits, though most people passing the booth had the reaction that I did - (1) you can just look at your clear water bottle (bad old BPS days); (2) what are you going to do if you are drinking too fast and you aren't near a calibrated water source - that is, so what good does it do other than tell you what you already knew, namely "I'm running out of water" (if you aren't drinking fast enough according to the target, just guzzle a little more); (3) the usual battery question. Apparently the product died on the vine, since I haven't seen it at any subsequent show or in ads.

In fairness, the guy's goal was to promote hydration. Most people do tend to not drink enough. I saw this yet again at this weekend's in-snow session of our Winter Camping course - people just don't realize how much they sweat off digging a snow shelter or snowshoeing, even when the snow is coming down hard. Since these were Boy Scout adult leaders who we were training to take the youth out snow camping, we could couch things in terms of having the Scouts paired up (buddy system) with a critical duty to remind your buddy to keep hydrated. So the trainees were supposed to practice by reminding each other (several still got a bit dehydrated).

Since most watches these days have interval timers on them, maybe a simpler solution would be to set some "hydration interval" to remind you to drink a bit every, say, half hour (yeah, yeah, too long for hiking on a hot day - pick an appropriate interval for your conditions).

Jim S
37 reviewer rep
749 forum posts
February 22, 2010 at 7:06 p.m. (EST)

Hey maybe I can program my GPSR to flash a screen that says DRINK.

I agree though that its a nifty device unless your life depends on it. Sort of like an air gauge on a scuba tank - as you suck your last gulp of air and it says 10% full. I still carry my water in a clear plastic coke bottle with a carabiner taped to it, so as long as my eyes are calibrated I'm ok.

I backpacked along the McKenzie river in Oregon last week and we had full water bottles but my partner and I both considered pouring out most of the water. It seems that unless there is high water from spring run off, the entire river goes underground for 5 miles. (see something missing under the bridge?) When we reached the "falls" there was no falls, just a

huge deep spring where the entire river re-emerged, at the bottom of steep gorge. We then had to hike another mile to get to point where we could get water out of it.

The spring, over 100 feet straight down.

The river - still 100 feet down

Jim S

2 reviewer rep
3 forum posts
March 3, 2010 at 12:18 p.m. (EST)

You're kidding with this right? Talk about gearporn. It might be useful if you could connect it where the water comes out of you. JUST DRINK THE WATER.

Look, just print out a picture of this thing and tape it to your drinking tube. Now every time you check it take a drink. Problem solved.

Alicia MacLeay (Alicia)
848 reviewer rep
3,902 forum posts
March 3, 2010 at 1:55 p.m. (EST)

Look, just print out a picture of this thing and tape it to your drinking tube. Now every time you check it take a drink. Problem solved.

That's pretty close to what I already do. If I think about my water, I take a drink. Seems to work.

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