DIY Platypus Pre-Filter Cap
Although I have misgivings about their durability, Platypus‘ 2L+ bottles remains the primary water reservoirs in my pack. It’s been a bit over a year now since I started using them. At the same time I switched over to Platypus, I also started treating my water with chemicals rather than filtering it. Both methods of treatment have their advantages and disadvantages, but lately I have been using chemicals almost exclusively.
A water filter, of course, filters out not only the invisible nasties that upset the stomach, but also the visible things things that don’t cause much harm but aren’t altogether pleasant: dirt, dead bugs, small rocks, and the like. When I moved to using chemicals I was just dumping the water into my drinking vessel direct from the source. Without any sort of filter, the water could sometimes be a bit gritty. Too textured for my taste.
As a first attempt to solve this I started to place a bandanna over the opening of the Platypus, and then poured the source water over that. That worked great for getting out the sediment, but then I had the problem of having a wet rag. If the sun is out, it dries, but the other 307 days of the year, the bandanna — even a synthetic Buff — became a bit of a hassle to dry. I wanted some sort of pre-filter that I could get wet without worrying about it.
The solution (like more than a few before it) came while browsing the BackpackingLight forums.








