It’s important to clean and sanitize your backcountry water filter or purifier before storing it away during the winter months. There’s a simple three-stage process for this that involves cleaning the filter to improve its flow rate, sanitizing the filter to kill any microorganisms inside it, and drying it before storing it until you’re ready to use it again. //

odd man out
Filters with a small pore size are susceptible to clogging due to hard water deposits. Most drinking water will have some divalent cations (Ca+2, Mg+2) that forms insoluble carbonate salts (from dissolved CO2) when it dries. The reason to rinse with vinegar is that the acid in vinegar (acetic acid) will dissolve the carbonates salts because carbonate is a base. It reacts with the acid to form soluble acetate salts and carbonic acid that decomposes to form CO2 again (mix baking soda and vinegar if you want to see the reaction). However the salts take some time to dissolve. So what I do is to run some vinegar through the filter, seal it, and let it set for a while (an hour or so), then flush that out and repeat until you get a good flow rate. Then run a large volume of tap water through it to get rid of all the vinegar.