For water purification, I use MicroPUR Tablets. They work great, but depending on where I fill my water bottle up from – I sometimes get "floaty bits" in the water. A traditional water filter would of course remove these.
What I need is a way to filter out these bigger particles when filling the bottle.
Read on for instructions on my home-made solution.
1. Buy yourself some replacement caps for the platypus bottle.
2. Cut a hole in the top of the cap. I did this with a 3/4" spade bit and a drill, which cut a perfect sized hole. You could use an exacto knife and a little care.
3. Using some landscaping fabric, cut out a small disk of fabric the same diameter as the outer rim of the cap.
4. Insert the filter fabric into the inner cap
5. Screw the cap onto the bottle.
Cut out 2 or 3 more disks of fabric and put them in your first-aid kit – now you have a field-serviable filter in case one should tear. Voila!
Total weight? Irrelevant – it's less than 0.1 oz, as it wont register on my scale.
Update on Aug 8th:
Hhhmm… Having this filter slows the rate of flow for filling up the bottle of course, but in a running water stream – it's no problem at all. In a lake, it simply takes too long 'scoop' water in with a sideways action – I think I'm going back to the drawing board on this one and looking for a fabric or mesh that is less dense….
Update on Aug 17th:
I've tried using 'metal screen mesh' cut from a small loose-tea strainer into a similar disk and it seems to be working well. I'll post pics later.