Took off for a day trip into to an alpine lake yesterday and when I got there found out that the filter and O-ring on my PUR Katadyn had died. I only use it in the summer and have neglected it for about 7 years so it didn't surprise me but did annoy me because I had to follow the inlet creek to it's spring for water since I couldn't filter which cut into my fishing time. Overall wasn't that big of a deal considering the lake was at 12,000 and the bowl it was in peaked at 12,750 I had a quick 1/4 mile hike up 500' and 2 full water bottles. If I was down lower it could have been a bit of an issue tho. So, whether you use your filter regularly or not pull it out occasionally and run a bit of tap water through it (assuming its not new in box) so when TSHTF your not sitting there kicking yourself while having to chew your water first .

Yea many of us talk about checking preps but to get into a monthly habit is better than talk when it comes down to it.