/ PRODUCT NEWS: Platypus® Evolves Pump-Free, Gravity-Powered Water Filtratio
Read more at http://www.ukclimbing.com/gear/news.php?id=5671
Hmmm... maybe someone hasn't thought through the physics... You're better off having the filter as low as possible (i.e. at the collecting end), to exploit the increased hydrostatic head, thus pushing water through the filter quicker...
With a bit of luck, you can probably fix this by swapping the short and long tubing sections around.
Unless there's something very cunning about the filter that means it works better with a low HH, or breaks if the HH is too high, but that wouldn't give much design margin.
or so as not to stress the pipe connections?
looks like a copy of MSR though.
It's amazing how many water purifiers are available, saves you from having to spend a fortune on bottled water.