MSR Sweetwater Purifier System 2011

The MSR Sweetwater comes with a system of parts providing far more functionality out of this unit than others. You get a pre-filter on the inlet pipe to keep the dirt out of the filter, and there’s a float for the inlet pipe to prevent it sucking up sludge from the riverbed. There’s also an adapter that allows you to attach the outflow pipe to various water bottles, which is very useful. The pump itself works very effectively with an impressive 1 litre per minute flow rate. An added bonus is a pressure valve that prevents you forcing water through the unit and bursting its seals. The basic filter removes bacteria and parasites; the system also comes with a purifier to fight viruses in the form of a bottle of sodium hypochlorite. But while this unit has a service life of 750 litres, which is far better than many others here, the Katadyn Pocket Filter has a service life of 50,000 litres, so if you’re using the unit regularly other options may be better for you. This is not the lightest option either, and if you just want a bottle to filter the water as you squeeze, this system may represent unnecessarily hard work.

Filter type 0.0002mm filter, carbon, plus purifier solution
Replacement cartridge £50
Effectiveness bacteria, parasites, viruses
Flow rate 1 litre per minute
Service life 750 litres
Packed size 19x5cm
Running costs based on cartridge replacement 1 litre = 11p up to 750 litres;
1 litre = 6.7p over 750 litres
Weight 320g
Made in USA
Number of stores in the UK 30
Stockist details – tel. (01629) 580484;


If you want one piece of kit that’s efficient and effective in a wide range of situations, the MSR Sweetwater is ideal. It won Trail’s ‘Best in Test’ accolade.

Review by Graham Thompson
First published in Trail magazine June 2011