Trails have a beautiful way of taking us deep into remote places, far from the hustle and bustle of daily life. And also far from plumbing, faucets, and drinking fountains.
Planning and carrying our water supply is an important part of backpacking. For one thing, without water, we die!
Less morbidly, sipping cool clear stream water on a hot day is one of the great joys in life.
If you’re new to all this, you might be wondering about the best way to carry water while backpacking. You could certainly throw a few bottles in your pack and hit the trail – no need to overcomplicate things. But since you’re here, I have a feeling you’re looking for something a bit more… optimized.
After thousands of miles and plenty of experimentation, I’ve tried and observed a lot of options for packing water while backpacking. In this article I’ll cover the most popular bladders and bottles, where to carry them, and how to set them up to work nicely with your water filter.
The Perfect Hydration System
To most effectively pack water for backpacking, you’ll usually need more than one container. You want a well-designed system with parts that all work together smoothly on the trail. Here are the important aspects of a good hydration system for backpacking:
- At least one container you can drink from while walking.
- At least one container you can refill without unpacking your pack.
- Multiple containers, so you can use one for electrolytes and one for plain water. Also handy in case one develops a leak.
- Extra capacity that doesn’t take much room when empty. This is especially important on long trails with the occasional dry stretch.
- At least one bottle (as opposed to a bladder and hose) for use around camp: cooking, hygiene, drinking at night in the tent.
- A filter or other water treatment method to make water safe to drink (more on this below).
- No unnecessary weight; everything is as light as it can reasonably be while still being functional.
Is it possible to meet all these requirements at once? Definitely! That’s what the rest of this article is all about.
Water Capacity
How much water should you carry for backpacking? The only way to answer this question for sure is to know your route, the water sources along it, and their current status based on the season and recent weather.
For example, on an early summer hike in the mountains you may be hopping streams every 30 minutes. During a fall backpacking trip in the desert, by contrast, you might have to pack water for a whole day, overnight, and part of the next day!
Most popular trails have resources available to help you plan. Look for recent water reports from info sharing groups on Facebook, comments in online forums or trail descriptions, or a Guthook / FarOut guide if one exists.
It’s very important to take responsibility for doing this research, because getting stuck in the wilderness without enough water is obviously dangerous.
The Helpful Answer
If you’re thinking “that’s not very helpful!” don’t worry, here’s a more practical answer: Most backpackers, most of the time, carry between 1 – 3 liters of water. The lower end of this range keeps your pack lighter, but you’ll have to stop more often to refill.
I personally think 2 liters is a good sweet spot; not too heavy, but also won’t have you stopping all the time to refill. If it’s hot or refills are few and far between, this might not be enough.
For longer trails through varied terrain (Colorado Trail or the PCT) or trails in dry areas (Arizona Trail) most people carry an extra 1 – 2 liters of water capacity. These containers are usually empty, but can occasionally be filled to get you through a long dry stretch or dry campsite. It’s nice when these containers are collapsible / foldable, instead of rigid bottles that take up more space. Keep in mind that if you’re using a gravity filter setup, the “dirty bag” can be used as extra water capacity too.
It would be very unusual for most backpackers to carry 6 or more liters, mainly because it’s too darn heavy! Only the most remote and extreme routes will require such large water carries.
Water Filter Compatibility
When backpacking, you’ll probably need to refill water from natural sources like streams and lakes. You’ll definitely want to filter this water, even if it looks clean, so you don’t drink bacteria and parasites that can make you sick. If you don’t have a filter yet, this guide to backpacking water filters is a good place to start.
A filter is part of your overall backpacking hydration system, so think about how it will interface with your water containers. Some filter systems attach directly to certain types of bottles or hoses for hands-free filling. Other combos are much less convenient or prone to spilling as you hold containers next to each other or pour from one to another.
To make this clearer, I’ve noted compatibility below for the most popular water filters, the Sawyer Squeeze (or similar Mini and Micro models) and the Katadyn BeFree.
Inline Filtration?
Most backpackers filter their water when they refill, either by squeezing, pumping, or letting gravity push it through the filter and into whatever container they carry it in while hiking.
“Inline filtering” is when you fill your hydration bladder or bottle with unfiltered water, and you filter it later by sucking it through the filter as you drink. This is usually done with a small hollow fiber filter like a Sawyer Micro, attached to the top of a bottle or spliced into a hydration bladder hose.
Pros of inline filtering:
- Water refill stops will be fast since you don’t need to wait for water to filter.
- You might need fewer water containers since you drink directly from your “dirty container” instead of filtering from dirty into clean.
Cons of inline filtering:
- Most filters don’t have a high enough flow rate for comfortable sipping; you really have to suck to get water through. This can be extra frustrating as the flow rate decreases due to dirty water.
- More unwieldy setup on your bottle or hose, since the filters aren’t tiny.
- If you hike in freezing weather, the filter should be packed away to prevent damage and then how do you drink?
I don’t use inline filtering, and have met several backpackers who tried it and didn’t like it. They all got tired of working so hard to suck water through their filters. If you’re going to try it, I would only recommend it in places with very clear water so your flow rate will stay high for as long as possible.
If you do want to try inline filtration, I’ll explain how it works with each method for carrying water below.
Hydration Bladder
If you’re coming to backpacking from another sport where hydration packs are common (like running or mountain biking) it may feel natural to use a hydration bladder for backpacking too. Many multiday backpacking packs have a hydration bladder sleeve built in, and elastic guides for the hose on the shoulder straps.
The Platypus Hoser 3 Liter bladder is the perfect size for backpacking trips, very popular, and my own personal favorite.
Pros of hydration bladders for backpacking:
- Very easy to drink from while walking.
- Weight is in a good location, centered and near your back.
- Holds a large amount of water (usually 2 or 3 liters) in a single container.
Cons of hydration bladders for backpacking:
- Can’t see how much water is left, so running out can catch you by surprise.
- Hard to get in and out of a full pack to refill during the day.
- When full, can change the way your pack fits against your back, especially if using a lightweight pack with minimal frame.
- After lots of use, they can eventually leak and soak everything in your pack.
Despite those cons, I prefer a hydration bladder as my primary water container while backpacking. I personally can’t reach water bottles in the side pockets of my backpack, so a hydration bladder is the only way I can comfortably drink while walking.
Tips for using hydration bladders:
- If your bite valve doesn’t have a shutoff and cover, replace it with one that does. I recommend the Hydrapak Blaster. It will keep your valve from getting dirty and prevent accidental leaks.
- Most hoses are the same 1/4 inch diameter, so it often works to mix and match valves and connectors from different brands.
- Consider adding a foldable Platypus 1 Liter SoftBottle to your hydration system as well. Sometimes a bottle is more convenient than a hose for cooking and hygiene.
- When filling your hydration bladder, squeeze out extra air before putting it in your pack. This ensures you can use the bladder’s full capacity and also gets rid of that annoying slosh… slosh… slosh… sound with each step.
Compatible Filters: Sawyer Squeeze / Mini / Micro, Katadyn BeFree, Platypus GravityWorks.
For the Sawyer and BeFree, you should install a connector kit on the hose, so you can quickly and easily disconnect the bite valve and connect a filter instead. This works best as a gravity setup, either using a larger Katadyn gravity bag for the BeFree or a CNOC Vecto for the Sawyer.
It’s also possible to set up a hydration bladder for inline filtering. Either splice a Sawyer filter into the hose, or use a large Katadyn or Hydrapak bag as your hydration bladder.
With the Platypus GravityWorks filter system you would simply hook up the hydration bladder in place of the clean bag.
Then connect the hose to the filter instead, and watch the water flow in.
Water Bottles
Bottles may seem like the simplest choice for carrying water while backpacking, but the options are surprisingly varied! Most serious backpackers use just a few options, and I’ll go over them each below.
Where to carry bottles?
The best type of bottle will depend on where you want to carry it, so first let’s go over where to pack your water while backpacking. To get a capacity of 2 or 3 liters, many backpackers will need a combination.
Water is one of the densest things we carry, so weight distribution is important. Try to carry water as close to your center of gravity as possible (close to your body, not the back of your pack) and balance the weight side-to-side.
Side Pockets: Many backpacks have side pockets that fit water bottles. If you’re able to grab and replace them without removing the pack (smooth rigid bottles like Smartwater are easiest) this is a great solution. If that doesn’t work for you, you’ll need to take your pack off or ask for help from a hiking partner every time you drink – definitely not ideal. You’ll also need to think about side-to-side weight balance.
Shoulder Strap Pockets: Some backpacks come with a shoulder strap pocket, or you can optionally add one. Depending on shape these can work well with Smartwater-style bottles (for Sawyer filter users) or flexible Hydrapak bottles (for BeFree users). They’re easy to reach and drink from, they position water weight in a good place, but some people – especially smaller hikers and women – find them awkward and bulky.
Back Pocket: Many backpacks have a mesh back pocket where you can slip an extra bottle of any shape. Bottles carried here will feel slightly heavier because they’re further from your center of gravity, and they’re impossible to reach without removing your pack. Back pockets work best for carrying empty bottles or extra water you won’t drink until later.
Now that you’re thinking about where you might carry your water, let’s jump into the best water bottles for backpacking.
Nalgene Bottle
I generally do not recommend hard-sided Nalgene water bottles for backpacking, though plenty of people do use them. They’ll get the job done if you already have them sitting around, but there are better options if you’re starting from scratch.
Pros of Nalgene-style bottles for backpacking:
- Very durable
- Can hold boiling water, great for keeping your sleeping bag warm at night on winter hikes
- Easy to fill from water sources
- Double as a “foam roller” for keeping those quads loose
- Cheap and widely available
Cons of Nalgene-style bottles for backpacking:
- Not compatible with most modern water filters
- Heavy and bulky
- Take up space even when empty
For backpackers who don’t regularly hike in sub-freezing weather and care about keeping their pack weight down, I don’t recommend Nalgene bottles. Most lightweight and ultralight backpackers use the following options instead.
Smartwater Bottle
Many thru hikers and experienced backpackers carry their water in 1 liter Smartwater bottles, the kind you can buy at the grocery store. This may seem like an odd fad, but it’s also very practical. Some versions even come with a squeeze-style sports cap that’s convenient for drinking on the go.
Pros of Smartwater bottles for backpacking:
- Very lightweight when empty (1.2 oz)
- Versatile (see Filter Compatibility below)
- Very cheap to buy (around $2)
- Easy to find at resupply stops, if you’re on a long thru hike
- Fits in side pockets of many backpacks
- Smooth outside is easier to slip in and out of pockets; smooth inside is easier to keep clean.
Cons of Smartwater bottles for backpacking:
- Wear out over time.
- Adds to plastic waste problem (though most hikers will reuse each bottle for a long time, making this less of an issue).
- Take up space even when empty.
- Not so easy to squeeze, if using to filter inline or backflush a Sawyer filter.
Compatible Filters: Sawyer Squeeze / Mini / Micro
Sawyer Squeeze, Mini, and Micro filters will all screw directly onto Smartwater threads, as will this Sawyer coupler ring which is also (mostly – sometimes slight leakage) compatible with Platypus bags. This creates lot of options:
- Filter from Smartwater bottle to another Smartwater bottle
- Filter from Smartwater bottle into Platypus bottle or hydration bladder
- Filter from gravity bag (like CNOC Vecto) into Smartwater bottle
- Use Smartwater bottle to backflush Sawyer filter
- Inline filter from Sawyer filter on Smartwater bottle
Collapsible Semi-Rigid Bottles
A couple manufacturers have designed collapsible water bottles in a similar shape and size to Smartwater bottles, hoping to provide the same benefits with fewer of the drawbacks. The two standouts are:
CNOC Vesica 1 L: I’m a big fan of CNOC’s Vecto bag, and I expect great things from this bottle too. It comes in two different thread types to fit both Sawyer and Katadyn filters.
Compatible Filters : Sawyer (28 mm thread), BeFree (42 mm thread). It especially shines as a squeeze bottle for inline filtering or backflushing, since it’s a lot easier to squeeze than a more rigid plastic bottle.
Hydrapak Stash 1 L: From the maker of the Katadyn BeFree filter pouches, but shaped more like a traditional bottle. It looks like the shape would be difficult to pull smoothly out of a side pocket, but I’ve never tried it.
Filter Compatibility: Katadyn BeFree
These bottles have a similar set of pros and cons, though the Vesica is closer to the size and shape of a Smartwater bottle if that’s your preference.
Pros of collapsible bottles for backpacking:
- Lightweight when empty (2.1 oz)
- Very versatile (see Filter Compatibility below)
- Collapses to small size when empty
- Lasts much longer than a disposable Smartwater bottle
- Compatible with Katadyn BeFree filter as well as Sawyer
- More squeezable than Smartwater bottle for squeeze filtering or inline drinking
Cons of collapsible bottles for backpacking:
- Can be hard to get in and out of backpack side pockets while walking (especially compared to a rigid Smartwater bottle).
- Have to hold it very carefully to avoid spilling while drinking.
- Costs a bit more than a Smartwater bottle (but lasts longer).
- A bit heavier than a Smartwater bottle
- Could potentially be punctured while hiking on a rough or overgrown trail.
Platypus SoftBottle
I always carry one or two of these foldable Platypus 1 L SoftBottles when backpacking. They take up almost no space when empty and slip easily into the back pocket of my pack. When full they don’t fit well in most side pockets or chest pockets, so they’re not good for drinking while walking. They’re perfect as extra water capacity that you’ll only use on a long dry stretch.
Pros of Platypus SoftBottles for backpacking:
- Lightweight
- Folds up very small when empty
- Surprisingly durable
- Semi-compatible with Sawyer filter (see below)
- Squirt nozzle is handy for backcountry hygiene
Cons of Platypus SoftBottles for backpacking:
- Don’t fit well in most side or chest pockets
- Not fully compatible with Sawyer or Katadyn filters (though can be made to work with Sawyer)
- Hard to fill directly from water sources
Compatible Filters : Saywer Squeeze / Micro / Mini with coupler ring (sort of). When connected to a Sawyer filter with the coupler ring, this combination is not totally watertight. My SoftBottles work well as the clean container in a gravity setup, but I would not use it for squeeze filtering or inline filtering.
They are also fully compatible with the Platypus GravityWorks filter system – just connect in place of the clean bag.
Bottle + Hydration Hose
This nifty Lixada Water Bottle Hose looks like an ingenious solution. It turns a Smartwater bottle (or CNOC Vesica or other preferred bottle) into a hydration bladder with a hose and bite valve.
Like a hydration bladder, you can easily drink while you walk without wrestling bottles in and out of pockets. And like a bottle, you can see how much is left and easily refill without unloading your pack. The best of both worlds!
I think this is a very creative solution and it works quite well. My only issue: water that sits in the hose too long tastes like plastic. I’m still waiting to see if that diminishes with time; if not I may swap out the hose for one from Platypus.
Pros of a bottle hose for backpacking:
- Easy to drink while walking
- Can see how much water is left without unpacking your pack
- Easy to refill
Cons of a bottle hose for backpacking:
- Vacuum builds in the bottle as you drink, making it slightly harder to suck water out.
- Some reviewers mention a chemical taste that goes away after a few uses
Compatible Filters: Sawyer Squeeze / Mini / Micro. Since this works with Smartwater bottles, it’s compatible with a Sawyer filter in all the same ways. It’s just an easier way to drink from them.
Recommended Combos
Still confused? I don’t blame you. If you don’t feel like deciding for yourself and want a one-stop shop for your entire hydration system, here are some combinations I recommend. You can certainly get creative and make other combos work, but these are all good places to start.
Note on Sawyer filters: Sawyer has three models: Squeeze, Mini, and Micro. Their compatibility is the same, so feel free to mix and match. I’ve listed the dual-threaded Mini below because it comes with the connector ring, is a good compromise between size and flow rate for most uses, and is less expensive than the Squeeze. I recommend you switch to the higher flow rate Squeeze for dirtier water, or the Micro only for very clean water. I only recommend the Katadyn BeFree for fairly clean water.
Hydration Bladder Gravity Setup
Buy these parts (total cost: $105):
- Platypus 3 Liter Bladder ($27)
- Hydrapak Blaster Valve ($7) – optional but recommended
- Sawyer Dual-Threaded Mini Filter ($29)
- Sawyer Connector Kit ($10)
- CNOC Vecto 3 L 28 mm thread ($23) as “dirty bag” for gravity setup
- Platypus 1 L SoftBottle ($9) – optional, but nice to have at least one bottle for hygiene and cooking
Capacity: 4 liters (filtered) + 3 liters (unfiltered)
Best when: Your pack has a hydration bladder sleeve, you already have a sense for how much water you drink while hiking (since you won’t be able to see how much is left in the bladder), and you’d rather carry a bit more water than stop to filter often (it can be a pain to filter into a bladder in a full pack). Also works well for routes with longer water carries because of the large capacity.
Smartwater Bottle Gravity Setup
Buy these parts (total cost: $65):
- 2 Smartwater bottles ($2 each)
- Sawyer Dual-Threaded Mini Filter ($29)
- Sawyer Coupler Ring ($3 alone, but is included with Sawyer Mini)
- CNOC Vecto 3 L 28 mm thread ($23) as “dirty bag” for gravity setup
- Platypus 1 L SoftBottle ($9) or CNOC Vesica 1 L ($13) – optional, increases water capacity without taking up much space when empty
Capacity: 3 liters (filtered) + 3 liters (unfiltered)
Best when: You can reach bottles in your pack’s side pockets, you prefer convenience of gravity filtering over squeezing. Also works well for routes with longer water carries because of the large capacity.
Smartwater Bottle Squeeze Setup
Buy these parts (total cost: $42):
- 2 Smartwater bottles ($2 each)
- Sawyer Dual-Threaded Mini Filter ($29)
- Sawyer Coupler Ring ($3 alone, but is included with Sawyer Mini)
- Platypus 1 L SoftBottle ($9) – optional, increases water capacity without taking up much space when empty
Capacity: 3 liters
Best when: You’re on a tight budget and/or want to save as much weight as possible.
This same setup could be used as a squeeze filter or an inline filter, depending on your patience for sucking water through a filter. If used inline, the Sawyer Squeeze model has a higher flow rate (pro) but is also bigger than the Mini or Micro (con).
This system can be annoying because you must release air pressure from the bottles periodically as you squeeze or drink, and the rigid bottles aren’t easy to squeeze. For an upgrade, see the next setup.
Collapsibe Bottle Squeeze Setup
This setup substitutes in at least one collapsible bottle, which makes squeeze and inline filtering much easier. When squeeze filtering between two Smartwater bottles you’ll have to stop and release the air pressure every so often, which this setup avoids.
Buy these parts (total cost: $53):
- CNOC Vesica 1 L, 28 mm thread ($13)
- Smartwater bottle ($2) – optionally this could also be a second Vesica
- Sawyer Dual-Threaded Mini Filter ($29)
- Sawyer Coupler Ring ($3 alone, but is included with Sawyer Mini)
- Platypus 1 L SoftBottle ($9) – optional, increases water capacity without taking up much space when empty
Capacity: 3 liters
Best when: Weight matters but so does convenience. This system is easier to use than two Smartwater bottles, especially for inline filtering.
BeFree / Collapsibe Bottle Squeeze Setup
The BeFree excels as a lightweight inline filter system for mostly clear water. Here’s a combo to make the best use of it.
Buy these parts (total cost: $71 including two Vesica bottles):
- Katadyn BeFree filter with 1 L soft bottle – $45
- Additional bottles like CNOC Vesica 42mm ($13), Hydrapak Stash ($25), or Hydrapak Lux ($20) – as needed for additional capacity and also compatible with the BeFree
Capacity: 3 liters
Best when: Water is clear, and you want to move fast and light with an inline filter setup.
If on a budget, you can replace the Hydrapak bottles with cheaper Smartwater bottles. These won’t connect directly to the BeFree filter, but you can always pour from them to the compatible bottle or vice versa.
More Backpacking Hydration Tips
Here are a few miscellaneous tips that didn’t fit anywhere else:
- Soft bottles and hydration bladders can occasionally spring a leak. Most can be repaired with a bit of gear tape, which I always recommend carrying in your first aid kit.
- When filtering water from very dirty sources, a prefilter will keep your main filter from clogging as fast. A prefilter can be very simple, just a thin bandana or buff (or a square of old pantyhose works great!) screwed between the threads where your filter attaches to the dirty container.
- If it’s hot out, electrolyte tablets are an easy way to replenish what’s lost in your sweat. I like Nuun Sport for their low sugar content.
- If using electrolytes or drink mixes, or even if not, clean your bottles periodically or nasty stuff will grow.
More Backpacking Resources
If you’re planning a backpacking trip, you might find these helpful too:
- Guide to Lightening Your Backpack
- It’s Time to Try Hiking in Trail Running Shoes
- John Muir Trail: 9 Things I Wish I’d Known
Or, visit the hiking resources center for even more tips, reviews, and trail guides.
About the Author
Hi there, I’m Alissa. I’ve had the pleasure of hiking the Arizona Trail, Colorado Trail, John Muir Trail, Tahoe Rim Trail, and countless shorter amazing trails throughout the US and abroad. I love solitude, big views, and a good lightweight gear setup. Learn more or say hi.
Excited about backpacking but need help getting started? The Backpacking Trip Planner Workbook will help you start off on the right foot.
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