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How to choose a water system for backpacking

Backpackers need more than couple of plastic bottles full of water to get from start to finish; you simply can’t carry enough water for drinking, cooking, and cleaning, all on their backs at once. Well, you could i guess – but who wants to carry 25 pounds of water all day long?

Nope, instead you need a water system – something to hold water, something to filter water, and maybe a straw to drink from as you hike. This article will help you on your way to choosing a water system.

What does a backpacking water system consist of?

I’m calling it a “system”, but that doesn’t mean it has to be complex. And, today, most companies that sell hydration gear for backpacking have simplified things to the point where you might only need two products – maybe three – and that’s it. Here’s what a water system might consist of: 

Gregory Hydro 3L hydration bladder for backpacking
  1. Reservoir: Something to hold clean water. Also called a hydration bladder.
    1. Reservoirs with straws: Think Camelbak. These reservoirs sit inside your backpack and have a plastic straw that comes out and clips onto your shoulder strap. They make it easy to drink while hiking, so you don’t have to stop moving to take a sip. You may find some reservoirs without straws, but most of them will have one.
    2. LIterally just water bottles: If that’s too fancy for your taste, all you really need is a couple liter’s worth of water bottles, and you’ve checked this box.
  2. Filter: Something to turn water from a stream or lake into water that’s potable, safe for drinking and cooking with. There are a lot of filters on the market, and for the most part there are two types.
    1. Gravity Filters work by filling up a container and placing the filter beneath, allowing water to slowly trickle through your filter and into your clean water reservoir.
    2. Squeeze Filters work similarly, but you squeeze the water from a container through the filter rather than waiting for gravity. They’re a lot faster.
  3. (Optional) Water Bottle: I bring a Nalgene with me, even though I already have a three-liter reservoir; it’s nice to have for meals or drink mixes.

How to choose a water system that’ll work for you

This isn’t going to be a long, drawn-out list of a thousand different things you have to consider, all of them given equal importance and at times contradictory. In short, this isn’t just another article designed to sell you products on Amazon or REI. For two reasons – one, because this decision really isn’t that hard, and two, because I simply don’t want to write that. 

Instead, I’m going to cover a few things to weigh in your final decision on this water system vs that one. It really isn’t that hard of a choice, and these days, there is no right or wrong choice. 

  1. Make sure you’ll have enough water
  2. Make sure you’ve got a filter
  3. Make sure it’ll work with your backpack.

1. Make sure you’ll have enough water

For most trips, this means having the ability to hold about a gallon of water total. That doesn’t mean you have to carry a gallon of water every step of the way. However, you do want the ability to have a full gallon on hand, to make camp easier or to ensure you can make

The best way to make sure you have enough water is to measure how much you freely drink on a day hike, and then adjust up or down depending on the trail you’re on. THings like weather, elevation, trail difficulty, and access to water will all influence the exact amount you should be carrying, but the baseline is just the answer to the question: “How much water do I drink on a normal day of hiking?” Once you have that answer, you can adjust for the demands of the trail!

2. Make sure you’ve got a filter

This one’s pretty self-explanatory. 99.9 percent of the water you’ll have access to on any given trail isn’t safe enough to just drink straight from the source. Instead, you’ll need to filter it. Water filters have gotten smaller, cheaper, and more efficient in recent years, and there are tons of great options. You really only need to make sure you have one – which one you choose doesn’t matter very much.

3. Make sure your water system works well with your pack

If you’re planning on using a hydration bladder, it’s worth spending a few minutes making sure it’ll fit snugly into your pack. My pack, the Gregory Baltoro 75, has a plastic clip where you can clip the bladder into place. It’s super simple and keeps the bladder from slipping around in the pack during the day. 

Before purchasing a hydration bladder, ask yourself a couple of questions: 

  1. Where in my pack is the bladder intended to go?
  2. How is the bladder supposed to be kept in place?
  3. Will the reservoir I’m considering work with that system?

It really is as simple as taking a look at your pack and making sure the reservoir is compatible. Pretty much all packs will work with all reservoirs, and it’s kinda unlikely that you’ll find something truly incompatible. But, since there are dozens of brands out there, it’s still worth your time to check.

Is it really that simple?

Honestly, yes. Maybe 10-plus years ago, when product choices were fewer and filters weren’t as broadly impressive as they are today, you’d have to spend more time thinking about this. But, from my research, one choice of water system is pretty much as good as any other. Prices are similar, performance is similar, and you really can’t go wrong. 

The main aspect of choosing a water system is just understanding what you need – a filter, a reservoir, and a water bottle. Anything less than that and you are missing crucial equipment. Anything more than that and it’s probably overkill.

My water system

Gravity filter and hydration bladder, filtering water on a backpacking trip

I have a Gregory pack, so it made sense to just go ahead and get a Gregory reservoir. Mine is a Hydro 3L, with a straw that clips onto the pack’s shoulder strap. I’m a huge fan – it doesn’t leak, it’s easy enough to fill and put back in the pack, and it holds enough water for 10+ hours of strenuous hiking. 

I also bring a Nalgene – literally just your standard 32 Oz bottle with a wide mouth. It’s great for meal time when I don’t want to be drinking from a straw, or for drink mixes like Nuun tablets or powdered Celsius (my secret weapon).

Finally, I use a Lifestraw gravity filter that, while slow, is great for filtering at camp because you just fill the bag, hang it from a tree, and move on with more important things. You don’t have to sit there squeezing the entire time, and you can multitask which is a huge bonus when you’re exhausted and the sun is going down. Mine is a couple years old and is the older version of this model, the Peak Series Compact.

My friend’s water system (I like his better)

My friend Tony, a more experienced backpacker than I, uses an ultralight Platypus squeeze filter system, with a filter and a few collapsible plastic bottles. It’s way lighter, way faster, and way more convenient than my water system, and it’s cheaper. 

The only downside, as with any squeeze filter, is that you have to be actively engaged with it the entire time. The upside, though, is that it’s way faster than a gravity filter, making it great for filtering at camp as well as on the side of the trail. Being able to filter quickly means you don’t have to carry as much water so long as you’re near a water source, because the detour of re-filling hardly takes up any time.

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