Katadyn BeFree filter failure – filter lets the dirt through

that’s disappointing

interesting idea about starch.  Google says Giardia are 10 to 20 microns.  15 micron starch grains would be necessary even though not sufficient.

I’ll have to try that.

I’ve had my Squeeze for many years.  It has definitely frozen but I shook all the water out of it.  It seems like it’s working.

After experimenting with quite a few UL filters, I’ve circled back around to the OG Squeeze.  It flows well in my gravity system and I’ve yet to clog one. IMO it’s worth the extra ounce or so for reliable performance.

I think this is a worthy thread to ask in light of the OP’s circumstance.

Has anyone heard anything or tried the ‘new’ Rapidpure POD system filter? Works on all 28mm standard threaded bottles https://www.rapidpurewater.com/products/pod-system

Replaceable filter lasts 75 gallons claimed. $20 for replacement. IDK about others, but I feel like I replace my sawyer squeeze filters before 75 gallons. Lets be real, no one gets anywhere close to 100,000 gallons in any sawyer squeeze/mini/micro/etc.

The question is how long does it take you to filter 75 gallons when in ‘typical’ use? I think it may be similar for a lot of people to when they eventually throw away their sawyer due to clogging.

Thoughts?

I really like the BeFree and the only one I wrecked was my fault – silt! The one I have now is still going strong after a number of trips. Passes the air test still. I always have bleach drops as a backup, but so far, no need.

Lets be real, no one gets anywhere close to 100,000 gallons in any sawyer squeeze/mini/micro/etc.

I’d have to agree, but I think the demise of hollow fibre filters (that have not obviously been compromised by filtering silty water) is most often attributable to long periods of storage, i.e. not being used, or storage without being prepped for such.  I had to replace my Squeeze after Covid kept me in the house for over a year and a half…it seized up and would not pass more than a trickle regardless of applying any of the documented methods of resurrection.

I’d bet that a Squeeze used every day would last a very long time.  I have no facts to support this assertion, but I am making it none-the-less :)

After experimenting with quite a few UL filters, I’ve circled back around to the OG Squeeze.

What’s an “OG Squeeze?”

As per the manual, the Filter Integrity Test is to squeeze some water through, then see if you can blow air back through the filter (with your mouth on the drink nozzle).  Can’t blow air –> filter is OK.

What’s an “OG Squeeze?”

The original Sawyer Squeeze filter…”full size”…not mini or micro.  OG is short for Original Gangster.

The original Sawyer Squeeze filter…”full size”…not mini or micro.  OG is short for Original Gangster.

Gotchya – I’m aware of the term, but I asked because there is a Co. that markets an “OG Water Filter” –

https://www.epicwaterfilters.com/products/the-epic-nalgene-og-water-filtration-system

The problem with the integrity test is that it is not reliable at all – I had blown some air through two brand new filters, and others had confirmed the same here in the forum – my original post on this is here.

And once we accept that even a new filter doesn’t pass the test but is still OK, how would one tell if a filter is truly damaged?

maybe a new filter passes air until it’s been wetted?

so, use the filter one time, then the blowing air through the filter test is more useful?

I wonder if the BeFree would be destroyed by the starch test even if it passed? Have you ever done the starch, have the filter pass, and then be usable afterwards?

I work with separations/filtration processes and so I definitely applaud your scientific approach. I was trying to think about how I would approach this in your place, without necessarily having access to various analytical equipment and materials, and I think the idea of filtering a standard dispersion and monitoring turbidity is a good approach. Obviously it would be better if you could quantify the turbidity, but that will be hard. The most significant improvement you could make would be to use a dispersion of particles that are more monodisperse (uniform in size). The problem with the starch is that the distribution of particle sizes is unknown and could be extremely broad. An inexpensive way to get uniform particles would be to use polishing grit. For about $10, you can buy a substantial amount of polishing power with particles in a relatively narrow range, e.g. 2–3 µm. Obviously, at this point it may not be worth any more time and money for you, but I thought I’d make the suggestion just in case someone wants to try it.

I just got some cerium oxide powder that I used to polish a scratch on my window

$15 from amazon

Maybe that would work

It might be difficult to determine if there was any that made it’s way through the filter

I assume that for a filter, they would have a solution that contained giardia and then see if there were any in the filtered water?  And some bacteria?

Yes, there are standard assays that are done to measure the reduction of pathogens (parasites, bacteria, virus particles) that pass through a filter.  For example, bacteria would be quantified in terms of colony forming units (CFUs), a filtration membrane would be challenged by a suspension with a known starting CFU and the CFU of the permeate would be measured. One might specify a log reduction value (LRV) of 4, which would mean that the CFU in the permeate should be less than 0.0001 of the original value.

Many virus particles will pass through the hollow core filters used for water filtration, but membranes with smaller pore sizes are used for removal of viruses, especially for pharmaceutical products.