If you're planning to venture out into the wilds (or semi-wilds) beyond the reach of mains plumbing, one of the things you'll need to get hold of is a supply of fresh water. Alas, a lot of the stuff that flows through the countryside is full of all sorts of nasties, both chemical and biological. This is where the Aquapure Traveller comes in. It's a bottle with a filter and iodinated sleeve in the cap. Fill it up, give it a good shake, leave for 15 minutes and then squeeze the water out through the cap. It'll filter out or kill off an impressive array of unpleasantness including cryptosporidium, giardia, E.coli and all sorts of other stuff that you really don't want to ingest.
At first glance, £44.99 might look like a lot of money, but the Traveller will purify 350 litres of water before the filter needs replacing. At £39.99 for the filter, that works out at about 11p a litre - considerably less than bottled water and you don't need a shop. Purifying tablets work out a lot cheaper, but they're a pain to use (and shouldn't be used for long periods of time) and make the water taste nasty. Even after using neutralising tablets to get rid of the taste, tablet-treated water doesn't taste as good as that which the Aquapure bottle squirts out.
If you need lots of water for a group expedition, then a mechanical pump filter may well be useful, but it's extra bulk and takes a fair bit of effort to use. If it's just you, the Aquapure bottle just replaces something that you're already carrying.
Drawbacks? We'd rather it was more conventionally shaped - the funky cranked bottle doesn't quite sit happily in all bottle cages, although it hasn't fallen out yet so it's obviously a reasonably effective fit. And some sort of indication that the filter needs replacing would be good, instead of having to make a note of how many times you've used it.
Other than that, it's a winner. It's not unique - water filter makers Katadyn do a bottle filter too, for about the same money - but it's effective and simple. Couldn't ask for more, really.
Verdict Could easily save you from becoming very ill. If you're planning to spend any amount of time away from guaranteed safe water, this is a top buy.
You usually know when filter devices like this have expired, because they've become unusable for some time beforehand!
On the two occasions I've tried filter devices like this, although the active filter might still be OK they've become blocked with particulate debris. Filtration gets so painfully slow as to be unusable. With the more expensive ceramic jobs you can clean them up with brushes, but that's not possible with these.
It's why I prefer pills, despite the disadvantages you mention. Filters are good enough if the water's not full of silt, though (I sometimes carry a Millbanks bag to use as a crude filter).
