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Reviews > Hydration Systems > Accessories > BonDry Hydration Pack Dryer > Test Report by Nancy Griffith

December 18, 2020



NAME: Nancy Griffith
EMAIL: bkpkrgirlATyahooDOTcom
AGE: 54
LOCATION: Northern California, USA
HEIGHT: 5' 6" (1.68 m)
WEIGHT: 126 lb (57.20 kg)

My outdoor experience began in high school with a co-ed scout group which made a 10-day canoe voyage through the Quebec wilds. I've been backpacking since college in Pennsylvania. I have hiked 1/4 of the Appalachian Trail and 2/3 of the Pacific Crest Trail. My typical trip is in the Sierra Nevada from a few days to a few weeks long. My base weight is lightweight at 15 lb (6.8 kg) while still using a tent, stove and quilt. Longer mileage summer trips are now stoveless.



in packagefront
Manufacturer: Fossil Outdoor, Inc.
Year of Manufacture: 2020
Manufacturer's Website:

MSRP: $19.99 US

Listed Weight: Not Listed
Measured Weight: 1.3 oz (36 g)

Listed Size: 17.5 in x 3.5 in (44 cm x 9 cm)
Measured Size: 17-3/8 in by 3-1/4 in (44 cm by 8 cm)

Made in Arizona, USA (YAY!)


close upThe Fossil BonDry (pronounced bone dry) is a hydration pack reservoir dryer. It is a rectangular shape of 17-3/8 in by 3-1/4 in (44 cm by 8 cm) which is made of sustainably sourced plant fibers and recycled plastic bottles. It is hypoallergenic and antimicrobial.

The BonDry can be machine-washed and can last up to six months. The website says that this was an estimate when they first printed the packaging but now their prototype is still working after a year of rigorous use. For best results, it is to be stored indoors with less than 40% humidity.


My initial impression was of a very lightweight package arriving that fit in the mailbox. The BonDry had been folded to fit into the envelope, so it has a crease in it that is floppy where the rest it is stiff. There is no reason that this would affect the usefulness, but I think I'll use the 'crease' on the end of the BonDry that sticks out of my reservoir.

The BonDry included simple instructions on the packaging. Initially, the BonDry seemed a little expensive for such a task-specific item. However, if I think about the gear that I currently own for drying hydration packs and how they still don't do an effective job, I have to rethink that. I own tube cleaning brushes and a drying hanger but still find myself buying bite valves and new hoses on a regular basis.

I dug out my hydration reservoirs and found that one only has a small diameter hole at the hose connection and so the BonDry won't fit inside. My other reservoir has a large roll-top style and no baffles, so the BonDry will work with it. I had to order a new bite valve for it though because the old one was too gross from not being properly dried! Let's hope that the BonDry will prevent that in the future.

So, as I waited for my bite valve to arrive, I did a little test by adding some water to the reservoir, sucking it through the tube, pouring out the water, blowing the hose water back into the reservoir, pouring again and then inserting the BonDry and setting a timer for an hour. Since my reservoir is 3L, the BonDry doesn't stick out of the top very far. After an hour, I checked and the BonDry and there was still quite a bit of moisture. I moved it around to absorb more and opened the reservoir to let more air in but after another 30 minutes, the reservoir wasn't dry so I went to bed. In the morning the reservoir was mostly dry but had a few drops in the corners. The tube seemed completely dry. Overall, this seemed like a much better drying cycle than what I used to see with the drying hanger. The BonDry didn't feel wet or really even damp when I pulled it out.


backThe instructions included on the package say to:
1) Rinse the hydration reservoir to remove anything other than water (like flavored drink residue)
2) Insert the BonDry into the opening with the end hanging out. If the BonDry doesn't fit because the reservoir has a baffle, the BonDry can be cut lengthwise down the middle to extend on either side of the baffle.
3) Let the BonDry do its thing. The water will be absorbed and transferred out of the reservoir via the BonDry.

On the FAQ page, they note that in order to facilitate drying the hose also, it is necessary to blow out any water into the reservoir first. After that it should do a pretty good job of drying the hose.

Machine washing should be done only if needed, like if some sugary drink or wine residue gets on it. Washing should be done in cold water on a delicate cycle.

The moisture from the reservoir should wick into the BonDry in an hour or so and then evaporate out in a day or so depending on how much of the BonDry is exposed outside the reservoir. But basically, after that first hour, the reservoir should be ready to use again.


The Fossil BonDry Hydration Pack Dryer is a simple yet effective way to dry out hydration reservoirs to keep mildew and other grungies from growing.

Initial Likes:
Simple to use
Quick dry time
Dries hose too

Initial Concerns:
Is my reservoir too large?
Will the new bite valve get gross again?



in reservoir
Drying new 2L reservoir
I'm not a huge fan of hydration reservoirs for backpacking (seem to prefer bottles) so much of my use was on day trips for hiking and mountain biking. It's irrelevant really since the BonDry is used at home after a trip. I wouldn't carry the BonDry on a backpacking trip.

I used the BonDry after every trip when using my hydration reservoir which was for a 4-day camping trip, six mountain bike rides, multiple short hikes, six softball games and other uses such for airport and motorcycle trips. I also used it after a backpacking trip where I carried various bottles and collapsible reservoirs with smaller mouths.

In the end, I used the BonDry to help dry my old 3L and new 2L hydration reservoirs (large-mouth) where the BonDry could lie flat, a 1L large-mouth bottle where the BonDry was slightly folded and underneath the small-mouthed opening of bottles varying in size from 1L to 4L.

Needles District, Canyonlands National Park, Utah: 2 days; 17 mi (27 km); 5,048 to 5,645 ft (1,539 to 1,721 m) elevation; 32 to 65 F (0 to 18 C); varied from calm with warm sun, to rain, snow and high winds

Lake Davis, Sierra Nevada, California: 4 days car camping, fishing and mountain biking: 5,886 ft (1,794 m) elevation; 55 to 91 F (13 to 33 C); mostly clear

White Rim 4WD Trail, Canyonlands National Park, Utah, 5 days; 103 mi (166 km) drive; 3,920 to 6,170 ft (1,195 to 1,881 m) elevation; 30 to 45 F (-1 to 7C); mostly clear

Mountain Biking:
Three rides around Lake Davis of 4 mi (6.4 km), 5.5 mi (8.9 km) and 20 mi (32 km)

Shelter Island Area, San Diego, California: 8 mi (13 km); nearly sea level; 65 to 70 F (18 to 21 C); sunny

Two rides of 11 mi (18 km) each on Coastal Trail / Haul Road, Fort Bragg, California: nearly sea level; 56 to 62 F (13 to 17 C); mostly clear


old hydrapak
Drying old 3L reservoir
As mentioned in the Initial Report, I needed a new bite valve for my 3L hydration reservoir due to it being too grungy to use. It turns out that the bite valve was obsolete and unable to be replaced, so I purchased a new 2L non-baffled, open-top hydration reservoir since the BonDry would work well with it.

The BonDry barely stuck out of the top of the old 3L reservoir so I kept it pushed completely down so that it would draw any moisture from the tube. I don't know if barely sticking out affects the effectiveness of the BonDry, but based on the website it sounds like it may affect drying time. In general, drying time is no issue for me so long as the reservoir dries before anything starts to grow inside. The BonDry fit easily into the new 2L reservoir and sticks out further, so there was no issue with drying at all.

I used the BonDry in my new 2L hydration reservoir after each trip (hike, bike, softball, etc.) and it was dry by next use. Even if it was the next day, the reservoir was mostly dry such that nothing was left in the tube to grow. I certainly never saw any grungies growing in the reservoir, tube or mouthpiece.

bottles in sink
Drying small-mouthed vessels
After a backpacking and then 4WD trip in Utah, I used the BonDry to dry out multiple water bottles. The backpacking trip required a carry of six liters of water apiece, so we used several collapsible bottles and hydration reservoirs without drink tubes. None of these vessels had a wide mouth that would accommodate the BonDry fitting inside for drying. So, after cleaning, I turned each vessel upside down in the sink and placed the BonDry beneath the mouths. It worked like a charm! I've never been able to get any of these vessels as completely dry so quickly before.

in nalgene
Drying 1L wide-mouth
After one trip, I used the BonDry to dry out my collapsible Nalgene bottle after using it for transporting wine and then washing it out. I had to slightly fold the BonDry in half lengthwise, but it fit inside easily and worked well.

My vessels either fit the entire BonDry or didn't fit it at all (the small-mouthed bottles), so I didn't have the in-between case where the BonDry could be cut lengthwise to fit as they suggest. But I will try that out in the future if my bottle collection warrants it. One possible idea is to provide a lengthwise split option that is half the width of the current split allowing the BonDry to fit into even small-mouthed bottles.

Overall, I'm very impressed with the BonDry. Getting water vessels completely dry is such an important task but one that is not always easily done. The BonDry worked very well and magnitudes better than any method I've used previously. I can't see how I'll ever have to contend with the grungies that require tedious cleaning, bleaching and brushing to remove. The BonDry removes all of the water in the reservoir and the tube.

I've used the BonDry so regularly over the test period that it seems like I either had water in the reservoir or was drying the reservoir with the BonDry at all times. I don't know exactly how many times I used the BonDry but I'd estimate around fifteen to twenty times. I haven't washed the BonDry but have just rinsed it after use. There has been no noticeable deterioration of the BonDry.


The Fossil BonDry Hydration Pack Dryer has turned out to be one of those pieces of gear that I desperately needed but didn't even know it. It works like a charm and performs a crucial task that is too easily overlooked.

Simple to use
Quick dry time
Dries hose too
Very noticeably better than my previous methods

Nothing at all

Possible Suggestion:
Provide narrower split options to fit smaller mouths

This concludes my Long-Term Report and this test series. Thanks to Fossil Outdoor and for the opportunity to test out this innovative product and find a better solution!

This report was created with the Report Writer Version 1. Copyright 2020. All rights reserved.

Read more reviews of Fossil Outdoor Inc. gear
Read more gear reviews by Nancy Griffith

Reviews > Hydration Systems > Accessories > BonDry Hydration Pack Dryer > Test Report by Nancy Griffith

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