A man trail runningA man  trail running

Hydration Reservoir Buying Guide

Hydration packs are an efficient and convenient way of carrying water and staying hydrated during activities. The key part of a hydration pack system is the water reservoir (sometimes referred to as a bladder) which is connected to a hose and valve that allows you to drink without having to slow down or stop. With developments in design, most modern sport-specific backpacks are now bladder compatible, making a hydration reservoir a worthwhile investment. Having a pack or vest with a bladder in is great for a number of activities such as hiking, running, skiing, cycling and more.

Before purchasing a hydration pack/reservoir there are a few key considerations:

  • What activity you will primarily be using the pack for
  • Reservoir capacity
  • Valve system
  • Additional storage and features

Why Use A Hydration Pack?

Thanks to their convenience and verstility, hydration packs and bladders can be used for a number of sports. The main benefits of using a hydration pack are:

  • Convenience – You can drink on the move with no need to stop and reach for a bottle. If running, it’s the best way of carrying water.
  • Maintaining a rhythm – Not only is it easier to keep a consistent pace, but thanks to being able to easily drink on the move you can take regular drinks and stay better hydrated.
  • Hands free use – You don’t have to carry anything throughout a run, or if hiking, your hands are free to map read on the move.
  • Stability and storage – You can avoid storing uneven bottles on your pack. As water is quite dense and subsequently heavy, you will greatly benefit from having it carried close to your back.

Different Types Of Reservoirs

types of hydration bladderstypes of hydration bladders

There are a range of reservoirs available, each with different features depending on their intended use/price point. The key features to look out for are reservoir material, shape and opening.


Typically hydration bladders are made from polyurethane or thermoplastic polyurethane. These are lightweight and durable materials that are thin, but will still last you a long time.

Some reservoirs will come with an antimicrobial treatment/technology that helps to inhibit the growth of bacteria on the inside of the bladder.


The shape of a reservoir plays an important role in the strength and profile of the bladder. In general, the less space the bladder takes up the better.

Look for low-profile reservoirs that quite often use a baffled construction in order to keep the size of the bladder as small as possible.


The opening is key for refilling and cleaning, so is an important aspect to consider. 

Some reservoirs offer a wide opening with a screw top. These typically allow enough room for you to fit your hand inside for cleaning and offer plenty of space for quick and easy refilling. They are usually strong and secure bladders.

Other reservoirs use a slide/zip-top opening. These bladders open completely at the top which allows for easy cleaning. They are very quick to open and refill, and are a great option if you will be refilling from a moving water source.

How To Choose Reservoir Capacity

Making sure that you have the right reservoir capacity is important for staying hydrated for the length of your chosen activity. Your choice depends on your sport, duration of activity and access to water (for example, the distance between aid station refills at longer running events).

The amount you should drink during exercise depends on a number of factors, including temperature and workout intensity. As a rough guide, you should look to consume between 0.5 and 0.8 litres per hour of exercise.

0.5 litre capacity is good for shorter running or walking where lightweight is key. You typically won’t find reservoirs this small, so water would usually be carried with a running vest and two small bottles.

1 – 1.5 Litres is a good minimalist choice for hikers and runners. Because you are not carrying as much liquid it is nice and lightweight, however, on hot or longer days you will likely need to refill during your activity.

2 - 2.5 Litres is a great all-round choice, offering a good balance of weight and liquid quantity. It is a good choice for hiking, longer runs without aid stations, and days skiing/snowboarding.

3 Litres or more is suited to longer hiking trips where you aren’t able to refill water regularly or want to minimise stops.

Different Types Of Valves

types of hydration pack valvestypes of hydration pack valves

The valve is the key part of any hydration system. It is what prevents your bladder from leaking, whilst also allowing you to drink. Nearly all valves that come with hydration bladders will have a bite seal. This means that the mouthpiece automatically seals when you aren't drinking - to drink, you just lightly bite on the valve.

Having a secure locking system is also key to preventing your reservoir from leaking. There are two main types of valve locking systems.

Twist On/Off - The valve requires a 1/4 or 1/2 twist to unlock and allow liquid flow. The twist can usually be done hands-free with a little practice.

Lever On/Off - The valve has a physical lever to block off the mouthpiece. They are easily operated with one hand and are the most secure way of preventing leakage. The lever is also usually set back slightly from the mouthpiece, keeping your hands away from the bite valve and preventing contamination.

Hydration Reservoir Accessories

To go along with your hydration bladder, there are a few accessories that are useful to ensure you not only get the most from your reservoir but also increase its longevity.

Cleaning Kit - Keeping your hydration bladder clean will make sure that your drink is safe to consume and your reservoir lasts as long as possible. It is especially important to thoroughly clean after any sticky sports/electrolyte drinks are held in your reservoir. Cleaning kits usually comprise of a brush for the main bladder and a brush for the tubing.

Valves - You can change to a bigger or smaller valve, or change to your preferred locking system. It's a useful spare to keep as with heavy use there is a chance you will need to replace your valve. Whilst most bite valves last for years, they will eventually wear out over time.

Insulation Kit - Insulation kits allow you to use your hydration pack in freezing temperatures, so are an essential add on for winter users. They usually come in a few parts that cover the reservoir, tube and valve to ensure that your drink doesn’t freeze solid.

Filter - In-line filters are a great and convenient way of ensuring your water is safe to drink. They replace your tubing and valve to filter your water as you drink - a must-have for remote trips when you may be refilling from natural water sources.

Additional Hydration Pack Features

hydration pack featureshydration pack features

Tube Routing – This is the slit/hole which allows you to route the tube from your hydration pack from the reservoir out of your pack/vest. Some packs will have more than one opening for this, allowing the tube to sit on either shoulder, whereas others will just have a single route. Occasionally packs with one route will have this set to one side, but typically it is central, allowing the user to decide which shoulder the tube will follow.

Quick Release Tube – For ultimate convivence when refilling the bladder, some reservoirs come with a quick-release tube system that allows you to disconnect the tube from the reservoir, leaving it in place on your pack whilst removing the bladder. This is especially useful for packs where the tube is routed.

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