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REI Tarn Hydro 15

The REI Tarn Hydro 15 has been a joy to take for a test ride. Each hike or bike ride, I came away appreciating the brilliant ingenuity of this uniquely designed adventure pack even more. Bonus points, it fits all three of us Gardner girls comfortably!

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The REI Tarn Hydro 15 has an impressive amount of cargo space, so much so that I needed to remind myself not to overpack it for my young children.

However, both my rascals happily loaded it down with trail “necessities” and never once complained about the heaviness of that spare pair of Keens, terrarium and barbies they insisted they needed.

The exterior mesh pocket came in handy frequently as my kids stuffed wrappers and other random things they picked up along side of the trail. They found their sweet spot picking up trash and blowing the sternum whistle with all their might.

The perfect spot for easy to reach sweet tea. See that double stitching? We love that!

This pocket is an excellent addition and we especially appreciate the carefully constructed stretch-mesh with double stitch binding.

We have had this pocket rip on other brands packs as the water bottle is pulled at all angles in and out of the pocket. There is extra protection where it counts.

Within 24 hours of the packs arrival we put the water resistant easy to clean fabric to the test. True to its claim both chocolate ice cream and ketchup came right out of the pack with a bit of soap.

We also love that it’s made from recycled materials and bluesign approved.

Tech Specs

  • Volume: 15 Liters
  • Weight: 15 oz
  • Dimensions: 15.3 x 8.6 x 6 inches
  • Hydration Compatible: Yes
  • Exterior Pockets: 4+
  • Hipbelt:Yes
  • Material: Recycled ripstop nylon; recycled nylon (bluesign approved)
  • Ages: 8-12 year olds
My eldest jumping stones with ease, this is a kid who wouldn’t wear a hydration pack hiking when this beautiful backpack arrived.

Key Features

  • Durable water repellent (DWR) finish to shed light rain and stains
  • Large mesh water bottle pocket
  • Padded back panel with built-in airflow channel for excellent comfort and ventilation
  • Buckled hip belt distributes weight
  • Zipper pulls and lash loops double as reflective accents for added nighttime visibility
  • Adjustable sternum strap with rescue whistle
Day pack for the kids, trail running pack for mama.

While recommendations for the Tarn Hydro 15 are for children between 8-12 years old, my rather petite 4 year old happily declared the pack was hers as it arrived near her birthday.

Maybe one day kid.

I was able to synch down the straps and fit the pack securely to her frame. It’s a little long for her torso but she doesn’t seem to mind.

I truly believe this well constructed day pack will last my family well over ten years (provided we treat our gear with love).

The pack fit my almost 7 year old much better with plenty of room to grow. She can easily loosen and tighten the straps on her own. The hydrating tubing is perfectly fitted to her torso regardless of whether or not I can convince her to put it in the right place.

My eldest was able to easily fill the bladder, pack snacks, her sunnies, an extra layer and binoculars. This routine of packing her own pack gives her autonomy and responsibility on the trail.

Best Uses for the REI Tarn Hydro 15

Day Hiking

Whether it’s a short walk to the park or climbing a first accent, the REI Tarn Hydro 15 is the perfect option.

It’s imperative to stay hydrated on and off the trail. There’s no doubt about it, my kids hydrate better if water is easily accessible and abundant. The bladder is easily to fill and clean which encourages repeated use.

Packed to the brim, this pack is still comfy enough that my very sensitive kid “forgot it was even on.” We especially appreciate the soft sunglasses pocket which also held special rocks or treasures.


Biking is really where this pack shines in our opinion. Plenty of pockets for tools, snacks, a spare tube and gloves. It stays in place as my kids turn tight corners without abandon.

They fly down the trails sipping water while simultaneously forgetting they are even wearing a pack. High praise I say!

Appearance and Functionality

The pack looks really sharp, and we love that REI has chosen to utilize recycled material. The DWR finish on the nylon works nicely to repel light rain and also makes for super easy cleaning with a damp cloth.

What Does it Hold?

What can’t this pack hold? An entire box of matzha, a soccer ball, sunnies, hats and a GoPro for a last minute park trip.

The Bottom Line

If you are a family that hike and bikes a lot and wants a light weight yet spacious hydration pack, the REI Tarn Hydro 15 is a solid buy.

Well made, reasonably priced and best of all easy to clean. This pack should last many miles both on and off the trail.

What We Love

The versitility of the REI Tarn Hydro 15 is amazing. I was pleasantly surprised how well it fit my small adult frame. I took the pack for several runs which allowed me to appreciate the lightweight yet secure fitting construction.

The hydration tube is easy to reach and stays in place even while sprinting. The bladder is easy to fill and doesn’t flop around while in motion.

My eldest has a hard time with pressure and texture in gear. While she was initially resistant to wearing a pack while biking and hiking, she has slowly come to appreciate the ease of use and comfortability of the REI Tarn Hydro 15.

The excellent back airflow and waist belt were definite selling points in getting her to appreciate the backpack. Now my girls have to take turns as to who gets to wear the pack.

I love the easy access to the pack while we are riding together.

What we aren’t so crazy about

We would like to see the shoulder straps a bit more padded like the REI Tarn 12. The thin straps get twisted which then twists the hydration tube. I’ve untwisted a very twisted tube and strap several times.

We love waist belts, we would love to see more structure to the belt with a pocket for a sunscreen or chapstick. With that said, we understand keeping the overall weight of the pack down is imperative.

Where to buy

The REI Tarn Hydro 15 can be purchased at REI for $59.95

© 2020, Tales of a Mountain Mama. All rights reserved. Republication, in part or entirety, requires a link back to this original post and permission from the author.

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