Started today after the meths stove was finished. estimate over half way complete. Cheap pipe fittings from a local plumbers merchant & a Webtex waterproof stuff sack/water carrier(ordered). 1 Micron tubular commercial filter sleeved onto modified pipework. Activated carbon cartridges made up & push fit into the assembly so can be replaced as necessary. just need an outlet tap and some more pipe fittings tmrw, Also a motorcycle small cargo net with hooks to be used for bag suspension - probably. Similar set up to those advertised on ebay for about £70, but seriously beefed up mass of particulate filter & activted carbon filter. Won't take up much more storage space but will last far longer and replacement filters can be put together a lot lot cheaper.
This is old tech, even the Egyptians were using it thousands of years ago (non activated - but basically the same just less efficient). I resent paying through the nose and having to bend over to companies for kit like this, just because some fancy words are used and the product may look a bit slick to some people. I can be my own worst pain when it comes to buying stuff, because the more I research the item, often the more I think - "I could make that" - and so it goes on....