Platypus GravityWorks Filter Review – 4.0L Water Filtration System

“I’ve only used the system once in the field…”

How can you review a product you have only used once in a real-world scenario? I don’t mean to sound harsh, but it seems like a somewhat premature review. You tested it in April of 2016. Didn’t you have time to use it more after that?

I have the 2-Liter system, and a friend has the 4-liter. We used his extensively this summer as the main filtering system for groups of up to 5 people, and it worked well for the most part, though the filter became progressively more sluggish in filtering over the course of the season despite regular back-flushes and generally finding relatively clean water sources. I wonder if using a Sawyer-style syringe might clear the filter better than the rather passive back-flush method Platypus suggests. My 2-liter system was defective out of the box with the ‘dirty’ reservoir having it’s welded seam too close to the bag’s edge and the side blew out on the first use.

It’s easy to populate the “pros” list on a new product, but it’s only possible to enumerate the real “cons” after extensive and heavy use in my opinion.

Hello Josh,

Thank you for the comprehensive review!

I utilized a similar setup last year on a 23 day trek through the Sierras. There are a number on configurations that this filter-tube-bag assembly can be used in and mine was a dirty bag with the filter inline to a drinking tube – worked like a charm. These types of filters do get sluggish and I found that filling a second platty with filtered water and forcing (squeezing) it through the filter in reverse (backwashing) worked well. I would also squeeze the dirty bag to fill my cooking pot quicker – man did I get hungry and couldn’t get some meals done quick enough!

None of the equipment failed (I’ve put an additional 20 days on it do date) and I would highly recommend this product for the following reasons:

Ease of use, application flexibility, reliability, durability, and cost.

Happy trails!

Mike

I have used the 4L version many times with my scout troop and concur with the review as well as comments above.  I have been pondering a 2L version for my personal trips.  Does anyone have experience with replacing the rather large Platy filter with the smaller Sawyer mini?  I’ve read a mixed bag of comments but no real solid evidence that this works well.  (There also appear to be a couple of different Sawyer minis on the market.)  My thoughts would be to leave the dirty bag at home and replace the Platy filter with the smaller/lighter mini.  I’m not a SUL/UL backpacker but always looking to eliminate unnecessary weight.  Appreciate any thoughts…   -dgl

Good review. On a trip two springs ago (around a year and three quarters) I finished my hike early and hung out at a lean-to for 3 days waiting for my ride. A group of 4 guys came in on week long fishing trip with one of these 4Liter filters (a couple guys came in the next day for a total of 6 in their group.) For the group, it performed really well. Considering the 12oz weight distributed over 6 people, it was about not quite half the weight of my Steripen. They used it extensively over the time I was there (their only clean water supply) and actually used one of the water bladders as a 2nd “dirty” water bag so they didn’t have to go down to the stream so often. I mentioned that they needed to keep the filter from freezing, and they disconnected it each time and put it by the fire as they went out fishing or in one of the sleeping bags at night. (Yup, 30’s-40’s during the day, teens-20’s at night. They had more problems with canisters in the morning than with the water.)

Anyway, the flow rates were very good over the time that I was with them, just a few minutes that emptied the dirty water into the clean bag. I also mentioned that a higher drop would increase the flow regardless of the position of the filter in a closed system, so they tried it…it worked and may have contributed to the fast flow rates for the three days I was there. One tied to the top of the lean-to and the other at the limit of the tube. Anyway, I usually don’t care for a filter system, way too fiddly for my (usually) solo needs, but was impressed how the system worked for volume their group used.

A better back flush for the Sawyer filter is to use a catheter syringe instead of the Leur Lok tip syringe that comes with the Sawyer.  Not familiar with the Platy filter but cutting the catheter tip to fit over the Sawyer output (not inside like the Leur Lok tip) gives a much better fit to really clean out the filter.  The tighter fit locks onto the filter and supports the filter so you can backflush by just holding the syringe, although you may want to support the filter as well.  A “slip tip” syringe may work as well but catheter was what I had and it worked.  From what I could see in the Platy site photos it (or a variation) should work on the Platy filter as well.