Purisoo bottle draws, filters and carries water in one convenient package
Two common ways of filtering water are portable pump filters, such the MSR Guardian, and bottles with built-in filter straws, like this one from Vapur. Korean startup Purisoo combines those two concepts into one, creating a water bottle that can draw water in from a natural source, filter it and carry it through the wild. The design keeps microscopic nasties away from your lips and ensures you're only carrying clean water around.
Bottles with integrated filters have become quite popular over the years and are on offer from brands like LifeStraw, Katadyn and Sawyer. Purisoo designers allude to a problem with how these bottles require you to fill up with untreated water before sucking that water through the filter straw. This can leave microscopic organisms like bacteria lingering around the top of the bottle, putting you at risk of accidentally ingesting them.
The Purisoo bottle actually filters as you fill, drawing water in through its triple-layer filtration system before depositing the clean water in the reservoir. At the other end, the Purisoo's filter handle removes so you can drink directly from the end of the bottle that stays out of the water source. There's also a 39-in (1-m) extension tube that can be dropped down into hard-to-access water that you can't simply dip the end of the bottle in. The filtration system is designed to be effective at removing bacteria and protozoa but only reduce, not eliminate, viruses, which is typical of water filters (as opposed to purifiers).
The Purisoo bottle works just like a traditional pump filter, only its integrated water reservoir means there's no need to carry and pump into a separate water bottle. The downside is that all that hardware takes up space inside the bottle, limiting capacity to 13.8 oz (408 ml), instead of the 16+ oz (473+ ml) you'd expect from an empty bottle. That's not a big deal if water sources are easy to come by, but if you have to pack greater quantities of water to carry with you, you may end up having to carry a spare bottle or two, limiting any size or weight advantage of the integrated system.
Whether the Purisoo offers any hard advantages over other available filtration and purification methods will vary by user and trip. But we've seen enough water cleaning contraptions over the years to know that different ones seem to appeal to different people. The Purisoo appears to be a thoughtful all-in-one solution that may very well find a receptive user base of its own.
The capsule-shaped Purisoo measures 3 x 11 in (8 x 28 cm) and weighs 20 oz (567 g). Its replaceable filter is rated at up to 1,000 liters (264 US gal) of water. The bottle and hardware are designed to be hand washed and are not dishwasher compatible.
Purisoo is currently raising money on Kickstarter, where it's offering the Purisoo with one filter and extension hose for pledge levels as low as US$69. It's nearing its way to success, having raised just over $35,000 on a $40,000 goal, with 13 days left.