Review: MSR Thru-Link

The MSR Thru-Link

Water bladders, commonly known as Camelbacks, are immensely popular. You fill the bladder, place it in your pack, attach the hose and drink whenever you want. There is no need to take off your pack when you want to drink.  this helps save a lot of time and effort on a longer adventure, but unless you want to carry a 3 litre bladder, you’re going to need to refill. The MSR Thru-Link is a simple and effective water filter for hikers and backpackers on the go. Fill your bladder with unfiltered water, plug the inline filter between the bladder and you mouthpiece, and continue hiking and continue drink filtered water.

What is the MSR Thru-Link?

MSR Thru-Link and a Hydrapak

The MSR Thru-Link is an inline water filter. It goes between your water bladder, filled with “dirty” water (unfiltered), and your hose. Once it’s all stowed in your pack you can drink as normal. The water is pulled through the filter and is purified on it’s way to the mouthpiece.

MSR designed and developed the Thru-Link for the US military so you know it’s tough. It is made of “ultrasonic welded housing.” It takes up next to no room in your pack as it is only 19cm X 4.2 cm in size and is hardly noticeable on your shoulders thanks to its light weight of 70 grams.

What does the MSR Thru-Link do?

It filters water, plain and simple. The water flow is rated at 1.5L per minute. We never tried to drink 1.5L of water per minute while hiking, we leave that kind of volume for IPA’s like Backcountry Widowmaker at the end of the trail. In MSR’s words, it has “fast-flow hollow fibres that remove pathogens, particulate & microplastics; activated carbon reduces chemicals, tastes and odors.”

MSR refers to this as two stage filtration. In essence, what this does is remove 99.9999% of bacteria, 99.9% of protozoa as well as particulates such as dirt, microplastics. It does not remove viruses. For that, you’ll need to bring along chemical additives. MSR states that because North American backcountries are regarded as low-risk for viruses, filters typically offer a sufficient water treatment method.

How well does it does it Work?

Scoop river/lake/dirty water into the bladder and close it. I used a Hydropak reservoir and the connection was a snap thanks to the quick connectors. They’re almost identical. Plug the Thru-Link into the bladder via the quick connectors, plug the hose into the Thru-link and begin drinking. It’s that simple.

On first use the Thru-Link does require some priming to get the water moving and move it did. Effort was only slightly harder than drinking from an unfiltered tube. Using a 2L bladder I rarely had to refill and could take constant sips without ever needing to take a break or take my pack off. There was no change in water flavour noticed.

The Thru-Link does need back flushing every 8 litres or so. This made more of a difference than I thought it would. Obviously, there are more particulates in the water that I was drinking than I realized. It’s always best to try and filter the clearest water possible to extend the life of your filter, and water that is heavily filled with tannins will end the life of any filter or purifier prematurely.

MSR Thru-Link Gravity Drip
MSR Thru-Link Gravity Drip

We tried to use the Thru-Link in a hanging gravity fed configuration in camp, but due to the nature of the reservoir I carry, I could not get the filter aligned properly. Most water bladders have a connection that points upwards, against gravity. When the MSR Thru-Link is attached, the result is somewhat phallic and ineffective. I’d still like to try and use the Thru-link in a vertical orientation to see how long a drip of 2 litres would take.


Pros: Light, small, and very well built with a great flow rate.

Cons: Best suited to only one person and is not effective against viruses. You will need a drink bladder with a vertical attachment to properly drip hang. This, in all fairness, is a problem with your bladder and not the MSR Thru-Link

Overview: The MSR Thru-Link is a great solution for backcountry enthusiasts who like to use water bladders and are on the move. It’s simple connection, low resistance while drinking and solid construction make it a great choice. It’s also fast to fill, because, you do not need to fill it. Open your bladder, scoop water, and go! Depending on the set-up it may not be ideal for a camp environment.

If you are interested in the MSR Thru-link, head on over to MSR to give it a further look:

Black Sheep Adventure Sports was supplied with a sample MSR Thru-Link for this review but this didn’t influence our review in any way.