making a light filter lighter

Posted by: lori

making a light filter lighter - 07/29/13 11:09 PM

Generally, I'm not much for ounce counting. But this one was serendipitous.

I switched my ULA gravity filter (discontinued, they had a dispute with the guy who designed it) from the old Hiker filter inside the bag to an in-line Platypus Cleanstream. It saved a few ounces over the original.

Last season I forgot to run bleach solution through it - when I got it out earlier this year, I figured out quick in a pre-trip test (always test before backpacking!) that the filter was clogged. It won't even back flush. My bad - shouldn't have let it sit unmaintained. It was a bummer as with back flushing it should have lasted for years.

I finally ordered a new filter - the updated gravityworks model. Same size as the old one, same basic shape, but when I took it out of the box... it felt lighter. So it was. And it turned out I could yank off the end caps that appear to be nonfunctional but merely decorative.

Weight for the filter setup in its bag at the start - 9.25 oz
Weight after replacement - 6.20 oz

Of course, it hasn't filtered water yet, so none remains in the new filter. This unit can't be pumped empty the way we do any of the pump filters. I ran a quart through the unit in the shower, shook as much out as I could to drain, and re-weighed. It added an ounce.

The decimal after the first digit isn't visible in the pics - it's measured in ounces in each pic.