BeFree prefilter

[Stumphges]

Would hydrogen peroxide result in a precipitation? If not, might be good bleach substitute.

[Daryl and Daryl]

Monty,

Just cleaned out my filter with distilled water  per your instructions.

Now letting it dry to see how it works.

Thanks,

[Ken Larson]

Has anyone tested the BeFree with a liter of water to observe its filtration time and flow,  AND THEN do the same with DualPacks 1.0 Micron Sediment Pre-Filter on to see how the filtration time  and flow is reduced?

[Jimmy Legs]

Jon, the pre-filter is not a Katadyn product, it is an aftermarket accessory.  I’m sure Katadyn’s response is that no pre-filter is necessary.

 

I just received my pre-filter and, contrary to what others have reported, my particular pre-filter is not difficult at all to install.  Sure it is tight fitting, and necessarily so, but not hard to install.  I just used some twisting action and had it fully installed in a couple seconds.

 

I did confirm that it is too larger to fit inside a Hydrapak and just small enough to fit within the BeFree soft bottle.

 

I’ll try to take some flow rate measurements with and without the prefilter when I get some time.

[Stumphges]

I took some flow measurements. Using a brand new BeFree. It was difficult to get an apples to apples comparison squeezing the bag, as hand position, force exerted, etc. are all uncontrollable variables. The most controlled test I did was a gravity hand until no more came out. Using tap water: without pre-filter: ~2 min; with pre-filter: ~2.5 minutes. Subjectively, I thought there was little difference and was pretty psyched.

 

So I took the new BeFree with pre-filter for an overnight this past weekend in the BWCA. Filtered lake water for 5 adults. Pre-filter became visibly soiled over the course of the first day and I thought “cool, it’s doing it’s job.” By evening the flow rate was getting pretty horrible, we were thirsty and so I decided to take the pre-filter off and “sacrifice” the naked filter to get some decent flow.

 

Result: No improvement in flow having taken the pre-filter off. Inescapable conclusion: Yes, the pre-filter gets visibly dirty with material that otherwise would have clogged up the filter, but DID NOT PREVENT the filter from getting clogged too. Conclusion: BeFree is not suitable for even the clean lakes of the BWCA and the pre-filter does not help matters.

BTW, I’ve also had BeFrees rapidly become unusable filtering water in the streams and rivers along the SHT, so this is not just a lake water issue.

Anyone have a suggestion for an alternative to the BeFree for waters with sediment?

[Daryl and Daryl]

I got pre filter.  It will NOT fit 3 quart hydropak.  Does fit be free soft bottle.

[Christian K]

I think if there is enough hardness in the water it’ll precipitate in the filter if as the water dries, regardless of bleach. Hardness just scales over time, period. Has to do with the water chemistry, and it’s super complicated and hurts my brain.

The purpose of bleach is to kill any biological material/bacteria in the water that would otherwise grow in the filter due to it sitting. Never thought about soaking it in bleach water. Seems overkill to me. Once it’s thoroughly dry, there usually isn’t an issue with bacteria growing. Some filter media breaks down with bleach. Probably not a problem for things like the BeFree or Sawyer, or else they wouldn’t recommend flushing with diluted bleach water. As recommended here and I think in another post, distilled water seems like the best flushing option for flushing (and albeit more expensive than tap water, its not any more expensive than a gallon of spring water at the grocery store). I’ll probably keep using tap water until I have a problem, and then switch to distilled :)

I always take my filter after I flush it with bleach water per the instructions, and swing my arm as hard as I can to remove as much of the water as I can (using centrifugal force). Never had an issue.

I’ve never used the BeFree, so IDK how the manufacturer recommends you flush, clean and store it. But for perspective, a 1 micron prefilter is pretty small, but also wouldn’t really inhibit flow. Definitely good for water with a lot of sediment. Typical RO drinking water treatment systems use 5 micron prefilters which is generally sufficient depending on what’s in the water.

I’m curious to know how the prefilter seals on the BeFree? Does the top lip of the filter seat into a depression on the BeFree? Water will take the path of least resistance. Doesn’t mean it won’t filter anything, but some water would get around the prefilter. That’s called short-circuiting.

[Stumphges]

Christian,

The pre-filter just jams up against the top of the filter housing. Certainly could be a gap there that much of the water flows through and evades the pre-filter. Hard to say.

[Shelley C]

1 1/2 year later do the commenters still like this prefilter or not?  And does distilled water work?  (Get the Ca++ out with distilled water soak THEN bleach?)

[Arthur]

The prefilters were a total failure in my hands.  See this for the real backflush story:  https://backpackinglight.com/forums/topic/how-effective-are-backflushing-and-storage-practices-for-squeeze-filters/#comments

 

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