I have finally decided to buy an MSR SweetWater purifier, hoping to increase my water consumption on the run. Indeed, the all-in-one bottles previously tested involve squeezing and sucking hard on the bottle, which has been proven rather irritating after a while. With a pump-based system, once the water has been purified and transferred into a regular container, drinking should be effortless.

The MSR SweetWater Purifier works in four stages:
  • Stainless steel prefilter to avoid clogging by larger particles
  • Silica depth microfilter against protozoa and bacteria
  • Activated carbon against chemicals (and foul taste)
  • Sodium Hypochlorite (ie. bleach) against viruses (and any filter-dodging bacteria)
MSR SweetWater Purifier
MSR SweetWater Purifier

As you can see from the picture, it is more fiddly than the all-in-one bottles. At 400g, it is significantly heavier too. The water is pumped mechanically through the prefilter and the intake hose, then passes through the main microfilter/carbon and gets out into another hose which can be connected to a container. Sodium Hypochlorite is added later, with a 5 minutes dwell time. If there wasn't a need for chemical addition, I would definitely try to hook up permanently the output hose onto a hydration bladder. In this case, I wouldn't even need to take off the bag to pump water in. But how can I easily add the bleach? I was thinking to use a syringe/needle, but all that gets very fiddly. Suggestions welcome!

As for the speed, I managed to filter tab water at 1.5L/min, but it'll be slower with more turbid water. After bleaching, the water didn't taste much of chlorine, which is definitely a big bonus.

Ultra pump