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Marmot Hydrogen 30

rated 4.0 of 5 stars
photo: Marmot Hydrogen 30 3-season down sleeping bag

This is an excellent 3+ season bag that is conservative in its listed temperature rating.

It comes with a heavy nylon stuff sack that is 6"x12". The stuff sack bottom is round. The bag easily stuffed into this sack, and compresses into a approximately a 6"x6"x6" cube. The 850+ fill power down lofts up quickly on its own, and it lofts up even faster if you climb in the bag. The bag's fabric, Pertex, feels good on one's skin and it is slippery smooth. This allows you to roll around and not take the bag with you. I have not weighed the bag. The manufacturer's listed weight is 21 oz.

The bag has a half-zipper. When fully zipped, it locks into place as the manufacturer claims. I have no problems getting into or out of the bag, despite there being only a half-zip. The zipper tape is stiff and keeps the wispy shell fabric from being caught in the zipper. Apparently, the 2008 version has a full zip.

I have used the bag twice in temps below the listed bag rating of 30 degrees F. Both those nights (10 and 11 degrees F) I was wearing a base layer top and bottom, liner socks, thick wool socks, 100 weight micro fleece pants, a 200 weight fleece vest and a thin hat. I was using a Therm-a-rest Prolite 3 (1" thick) underneath me. Both nights I was in a tent.

I have also used the bag on multiple nights in the mid 30's and lower 40's. Each time I slept in just a base layer and a thin fleece hat. I had a a Therm-a-rest Prolite 3 (1" thick) underneath me. I was toasty warm. I would recommend this bag to a friend.

Design: Mummy
Fill: 850 + fill down
Temperature Rating: 30 degrees F
Weight: Store listed at 21 oz.
Price Paid: $209

This is an extremely lightweight high quality down sleeping bag that is part of the reason Marmot continues to dominate the high-tech sleeping bag market. Materials selected combined with 900 fill down have set a new standard in lightweight camping. While not rugged enough to be carelessly ground into Joshua Tree mini-boulders, this bag is a must have for those smart enough to invest in a 5 dollar ground cloth before they throw their $300 bag out on the desert floor. Jeez, you’d think.

Uses: 25-45 degree semi-minimalist camping, hiking, when the misses kicks you out for the night and you don’t have a doghouse, sudden visits from your Army buddy.

Pros: super light weight, great warmth at listed rating, great craftsmanship as to be expected.

Cons: too little leg room as most mummy bags have, can it take more than an ounce or two to let someone cross their legs without getting ankle bruises? Cost! But 900 fill which was unheard of a short time ago is really very expensive so if you can handle the cost, get this bag.

Design: Mummy
Fill: 900
Temperature Rating: 30
Weight: 21 ounces for us short guys

I love my Hydrogen! I have had it for almost two years now. I have used it in temps as low as 20 degrees, I was a bit chilly that night! Generally I am quite toasty in it. I tend to sleep warm.

You can't beat the weight and compressability of this bag! I can fit the bag, my inflatable sleeping pad, and extra clothing in the sleeping bag compartment of my pack.

I have also found the fabric quite water resistant. I have had dew on it many times, no problem. I also love the simple one drawstring hood. No velcro! The only challenge for me at 6'4" is the half zipper, but for the weight I can live with it.

I love this bag so much I am now looking at getting the Lithium 0 degree for snow camping.

Design: Hydrogen (long)
Fill: 900 fill
Temperature Rating: 30
Weight: 1lb, 8oz
Price Paid: $280

I've been using my Hydrogen for over six years and I've taken it with me on many canoe camping trips, bicycle tours, and backpacking trips. (Used it for around 50 nights in total.)

I have to admit that I'm pleased with my purchase but I do have some small quirks:

- Outer fabric developed a small tear. I'll let that go because it could have been a packrat.

- Zipper is only half length. Makes it hard to ventilate and sweating in a down bag can't a good thing.

- Silicone coating in the stuffsack is flaking off in large patches.

- Temperature rating is a little ambitious. (Aren't they all?)

As you can see, they are more or less minor annoyances. If I had to do it all over again, I'd purchase the Hydrogen again for sure.

I wanted an ultralight down bag, comfortable to 30°, to camp at 12,000 foot elevations in the summer. The 30° Marmot Hydrogen, high loft down sleeping bag seemed to fit the bill.

On 2 nights it got down to 37°. It was a cold night’s sleep. On Marmot's website they rate the bag 39.2° for a comfortable night’s sleep, 30° at the lower limit. While I would have made it at 30°, it wouldn’t have been a good night’s sleep.

I like everything about the bag except being cold. I am going to get the Marmot Helium, a 15° bag with a comfort rating of 27.7°. These are both great bags but if you like to sleep warm in high country summers and do ultralight backpacking, go for the extra 4 oz of down and get the Helium.

Design: Mummy
Fill: 850 down
Temperature Rating: Says 30 degrees but better 40 degree bag
Weight: 28 oz
Price Paid: $280

My bag choice for '06 AT through hike. Sorry, 900 fill no longer available. Hundreds of nights. Good temp rating for a thru. I never had to switch to a summer bag. Temps dipped into the teens during early spring in the Smokies. Chilly but bearable under twenty degrees. Most of the time a bag is in your pack and the Hydrogen is brilliant there. Packs small and light. Looks cool in black!

Cons- a bit pricey but you could spend more.
- questionable durability, although I never had a problem.

I recommend this bag.

Design: mummy
Fill: 900 fill
Temperature Rating: 32ºF (0ºC)
Weight: 1 lb. 4
Price Paid: roughly $350

I got this bag because it was the lightest one I could find (1 lb 5 oz). I only ended up using it for 2 nights at Joshua Tree--after the second night I a small hole in the bag, and down feathers were leaking out. During the 2 nights I slept in it, I was surprised because I was a bit cold. I would estimate the temperature to be about 35 degrees, and I was also inside a tent with another person. I was only using 1 sleeping pad though. I returned the bag and have now upgraded to the Helium version, which is 8 ounces heavier (1 lb 13 oz) and does not pack as small as the Hydrogen.

Design: mummy
Fill: 900 fill down
Temperature Rating: 30 degrees F
Weight: 1lb 5 oz
Price Paid: Retail

When I got this bag I was very excited about it. But after only one night, I woke up to find my tent full of little little 850 count down feathers. Somehow, I ripped two small holes near the foot of my bag and another hole in the small of my back. I am a restless sleeper but this was unacceptable. I love having a bag that is so light, but next time I will trade a few onces for a bag that does not have such a thin skin.

I bought two other Hydrogens, one for my wife and one for my son. They are going back to the store.

Design: mummy
Fill: 850 fill down
Temperature Rating: 30
Weight: 1.7 pounds
Price Paid: $320

I Love This Bag!!!


  • Lightweight
  • Comfortable
  • Packs small
  • Warm

My first use was a 3-day backpacking trip. The bag is roomy and lightweight. The full length zipper is great because you can use the bag similar to a quilt for warmer weather.

Source: bought it new
Price Paid: $279.16

Had this bag for about three years now and have used it over 40 times in the backcountry. Initially it appeared delicate to me but a recent inspection shows it to still be in "like new" condition. I like the size, cut and performance, but still carry my synthetic if it looks like lots of rain on the horizon. Enough room in this bag to layer up if it turns colder than expected.

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Price Current Retail: $389.00-$399.00
Historic Range: $18.95-$419.00
Reviewers Paid: $209.00-$350.00
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