Master Blaster

[Chris R]

Came back from a recent trip with a thoroughly clogged Platypus filter cartridge on my MYOG gravity filter system. Decided some drastic action was needed so rigged up an adapter to fit the outlet hose to a basement tap that had a std. garden hose thread.

The reward was a satisfying belch of brown gunk expelled from the inlet side of the filter and a filter that now runs like new. Not exactly a solution to use in the field but definitely an effective way to restore a filter.

[Jon Fong / Flat Cat Gear]

I would have significant reservations about using that method.  The reason that the design center for the filter is probably in the low psi range.  A water column 10 feet tall would deliver a pressure of a little over 4 psi.  House water pressure is more than likely north of 40 psi.  There are chances that you have damaged your filter and there really is no way to tell if it is damaged or not.  The Manufacture probably will not give you any advice on this.  My 2 cents.

[Erik G]

Don’t know if it’s considered “legit” by Platypus, but Sawyer makes a faucet adapter and encourages a high pressure back flush at home. My gut feeling (pun?) is that the Platypus is constructed in much the same way (hollow fibers) and can probably handle similar pressures. But, as Jon states, we’ll never know for sure…

I’m gonna keep doing high pressure back flushes on my Sawyer SP140, FWIW. So far so good :)

[Ken Larson]

Chris….Where did you get this part?

[R]

Seems a rudimentary test could be done by leaving water samples in sunlight in hopes of growing algae.  If you have a bloom sample, filter it and see if that also blooms.

 

[Jon Fong / Flat Cat Gear]

what about bacteria?

[Chris R]

I did remember seeing a post about a device sold by Sawyer, otherwise I’m not sure that I would have tried it. Of course they may have built something into their adapter to limit the pressure. I did take the precaution of not cranking the tap fully open though. I’m on a private well so not sure what the pressure is. It must be possible to put a lot of pressure on those big syringes that come with the Sawyer filters or even with the squeeze bladder. Wonder what pressure is put out by the hand crank pump filters? Is here a way of testing that without an expensive gauge?

I bought the bit on the end from a farm supply store. Just a mind boggling array of bits for supply water to and extracting milk from a variety of farm animals. Fun places to spend time browsing!

 

[Chris R]

The first filter we ever bought was a General Ecology First Need Deluxe. The manual for that suggested using food dye to test for filter integrity.

[Roger Caffin]

You can solve ALL these problems by switching to UV sterilisation, with for instance a Steripen.

Cheers

[Chris R]

Had a steripen fail. Not going back there.

[Roger Caffin]

@Chris

Which model Steripen failed?
I ask because we know that the original model (Adventurer) did have some faults, but the latest models (eg Classic3) have been very reliable.

Cheers

[Chris R]

Think it was an Adventurer. Lights stopped working after it got caught in the mother of all cloudbursts while in an outside pack pocket. Never really worked for us as a couple and didn’t fit our water bottles anyway. I like the way a gravity filter works while we’re getting on with other stuff.

[Sam Farrington]

“There are chances that you have damaged your filter and there really is no way to tell if it is damaged or not. ”

Can you find some infected water? Maybe just take a sample from a sinkhole in the woods where the animals drink, but clear.  Don’t want to make matters worse if your filter survived the backflush.  Run the sample through the filter and send a filtered sample to your state lab to be tested for drinking.  If nothing shows up, the filter is probably OK, and it is safe to use your power backflush set up.

Or you could just email the filter manufacturer and ask how much pressure is OK for backflushing.

[Erica R]

The platypus gravity filter has an easy integrity test: https://d1l67pfsx3wblg.cloudfront.net/pdf/GravityWorks_Ins.pdf

The same inegrity test works for the BeFree.

There is a trick to using the platypus filter. When you load up the dirty water bag flow will be minimal. Perform the integrity test by blowing into the clean output tube. A few bubbles will go into the dirty bag. Flow will be normal after that.

I had a disconcerting experience with the platypus. It had been in dry storage a few years; I was using the BeFree for mostly solo trips. Because there were friends on this trip, I brought the Platypus… better for groups, I thought. Well, I should have tested it at home. When we got to the first camp, the platypus barely worked. I considered going back to the car to get the BeFree, but that would have blown the trip – we had definite reserved campsites.

So… I did get enough water through the platypus finally. The next day we boiled some water. After that the platypus slowly improved, and by day 4 it was working pretty well.

[Chris R]

Erica, thanks for the heads up on the blow test. I have actually tried that before and observed that I couldn’t blow back through the filter not knowing it was a test for filter integrity. Tested mine and I’m sure everyone will be happy to know they are fine. Will have to disinfect them again now!

For info, the same type of hollow tube membrane is used in reverse osmosis systems that run at high pressure so it looks like they are more robust than many assume.

[Ken Larson]

SAWYER SP119 – Screw on Filter Faucet Adapter

https://www.sawyersafetravel.com/sp119

Faucet Adapter Assembly with screw on connection. Used for cleaning all Sawyer screw on filters.

 

 

 

 

 

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