Review: Osprey HydraForm Reservoir

A water reservoir doesn’t need to be anything special. Typically just a rubber bag with a hose coming out, a water reservoir’s only purpose is to store water and distribute it easily. The Osprey HydraForm takes a bit of a departure from your typical reservoir and gets a little fancy with the design, but do these features really add to the user experience?


When you’re on the market for a water reservoir, there’s not really much to think about. Like most people in the market for an independent water reservoir, I wanted hydration capabilities because I had a pack that didn’t include a reservoir. I took a trip to REI and narrowed my search down to the Platypus and Osprey brands. I didn’t want a CamelBak because I already had one, and I didn’t want a GEIGERRIG because I didn’t want the extra weight or cost of a pressurized system. I was leaning toward the Platypus Big Zip because it looked really easy to clean, but I was worried about leaks. So then it was between the Osprey HydraForm and the Platypus Hoser.

The Hoser was cheaper and looked simple, so I was actually planning on buying it over the Osprey until I opened my mouth. I asked a nearby REI associate which bag he recommended, and of course, he recommended the HydraForm because of its extra features. I asked him if he had ever used the Platypus and he replied:

Oh ya, all the time! It’s what I carry the booze in.

After standing in that REI aisle comparing all the reservoirs for what seemed like an hour, I decided to give the Osprey a shot. Call it curiosity, but I wanted to see how a brand that I had never purchased before would perform.

And you thought nobody could care so much about a bag with a hose.


I used my REI membership to get 20% off with a coupon that was available at the time, which priced it around $28. It’s a buyer’s market on these things, and they are available everywhere. Expect to pay around $28 for a good deal on the 3-liter version, but some extra effort online might land you one for around $24. Don’t pay over $30, it’s widely sold for less.


So, what’s so fancy about the Osprey HydraForm? The most noticeable feature is the plastic sheet on the back that keeps the reservoir rigid. The purpose of this plastic sheet is to take advantage of smaller daypacks that don’t have any framework installed, acting as a makeshift internal frame. To me, that seems gimmicky, seeing how the bag doesn’t mechanically secure to the backpack in any way, but I still do like this feature for other reasons.

The main reason I like the internal frame of this reservoir is that it makes handling the bag so much easier. The bag doesn’t have the freedom to contort and shift around as much, which makes it easy to control, slide in and out of my packs, and it prevents the reservoir from slouching to the bottom of my packs. The plastic sheet is held in place by nylon fabric that is actually elevated from the sheet itself, similar to how some backpacks provide back-ventilation. I thought the nylon fabric would deteriorate or slack after being in contact with trail dirt, but it hasn’t even slightly hinted at either failure.

The internal frame is well-constructed and beautiful. Based on my testing it seems very strong and usable, and I have come to appreciate it. In fact, with the internal frame and ventilation, it makes me wish there was a way to strap the HydraForm reservoir to my back without any pack at all! Just slide on some $3 straps and take off for a quick desert run. How about it Osprey?

Moving to the front of the pack it will start to look like a normal reservoir but there is still a lot to talk about here. My absolute favorite part about the front of the pack is the plastic spine that travels the length of the reservoir. Not only does it direct the hose upward and prevent annoying pinches at the base, but it doubles as a handle! The spine is only connected at the base and the fill opening, which forms a long plastic handle to grab the bag from. When I first held the HydraForm in REI I didn’t think much of it, but now I can’t live without it. The handle makes it so much less awkward to carry a reservoir around camp or at home.

The spine also doubles as a guide for the hose. Most reservoirs incorporate some function that points the hose in the right direction, but the spine integrated into the HyrdaForm reservoir actually guides it several inches. After the tube leaves the guiding spine, it is directed into a fabric loop by the fill port, after which the hose can be manipulated freely. I remember having constant pinches with other reservoirs in the past, but the way the HydraForm directs the hose along the body has actually prevented me from encountering a single fold or pinch. Well done.

Moving down to the bite valve, you will find the tube to be thick, sturdy, and resistant to bending and pinching. The bite valve itself employs a 360° rubber gasket that forms a seal against a red hourglass-shaped piece of plastic. This is appreciated because it allows good flow and it can be used from any angle. Well, at least that’s the idea. The problem I have is that the bite valve housing is a bit awkward to use. In order to lock the bite valve, you have to pivot the mouthpiece 180° outward. This means that when you want to lock the valve, you have to rotate the rubber mouthpiece away from the hose until it is inline, essentially extending the hose an inch. While this doesn’t sound like a big deal, I have found it to be the biggest nuisance with the HydraForm. When locked, the mouthpiece becomes the exposed end of the hose, which means that it is going to touch everything when you sit, take your bag off, or move around. Because the valve lock forces you to unnecessarily expose the mouthpiece, it increases the chances of physical damage to the bite valve and the chances to transfer foreign objects and bacteria to your mouth. Osprey could easily fix this by allowing the valve to lock in the other direction, snug next to the tube. As much as I hate this problem, I still love the bite valve for a different reason.

Osprey easily redeems the value in the bite valve by adding a magnet, as well as an independent magnetic clip that you can attach to a backpack strap. This allows the user to magnetically attach the bite valve to a location on their pack when the hose is not in use. I use this feature every time I use this pack. It is amazing to effortlessly grab the hose, drink some water, and loosely place it next to the magnetic clip until it snaps in place. I have found the clip to be especially useful when attached to the shoulder strap on my SAR pack. I have fallen in love with this feature so much that I will never buy another reservoir without a magnetic attachment point on the bite valve.

One thing I hate about all reservoirs is keeping them clean. The HydraForm is your standard BPA-free rubber bag with a proprietary antimicrobial coating, which is pretty common marketing on the reservoir market. However, what bothers me with reservoirs is that even after you clean it, there is still water left in there. Storing water in a water-tight container for extended periods of time can make your reservoir slimy and gross, regardless of the coatings and claims. Luckily Osprey had the foresight to include a wide-mouth filling port, which allows me to get my hand in there and soak up all the excess water before storage. I also recommend that you place the bite valve inside the reservoir, and let it hang upside down overnight to air out. While we’re on the topic, yes, there is a loop on the bottom of the reservoir for hanging purposes.

Before wrapping up, I want to bring up a quality issue I have noticed on the reservoir itself. The bag seems to be prone to have very small abrasions, brand new from the factory. I have personally purchased 3 different Osprey HydraForm reservoirs, and 2 out of the 3 have had a single small abrasion that does not actually pierce the reservoir. As far as I can tell, these cuts exist from the factory, as new cuts have not formed on my reservoirs, even after heavy use. Also, of the reservoirs affected, each seems to have only one abrasion on the front side of the bag, to the left of the spine.

This small abrasion really worried me for a while, as I expected the reservoir to fail under the pressure of a fully-packed and cinched-down backpack. To my surprise, I’m pleased to report that I have not experienced a single failure on any of my HyrdaForm reservoirs to date. Regardless, it is still in the back of my head when my pack is really full. There would be few things worse on a backcountry hike than 3L of drinkable water wasting itself all over the contents of your bag.

I have very few complaints on my 3L HydraForm reservoirs and have found it to be a reliable and pleasurable reservoir on many backcountry adventures and day hikes.

RigCast Grade: A-

1 thought on “Review: Osprey HydraForm Reservoir”

  1. I have the smaller(est) Raptor and rellay like it. Mine doesn’t have wing’ pockets at all, so I don’t have that issue, LOL. My take though, I have the 6, I think, and I love it. Super comfortable and stays put rellay well. I typically will ride without the waist belt and just buckle up for the decent. Even without the waist belt, it stays put nicely. I did have some problems with a leaky bladder but REI took care of that and the second one has been solid. Provided they don’t leak (which I don’t think is normal) the bladder itself is a pretty cool design.My only real complaint no insulation. Not a huge deal, but would be nice for sure. I like cold water.

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