Help with Water Filters, Please?

[Oma-n-Opa]

Has anyone used this product:

http://www.gofastandlight.com/Water-...tinfo/W-R-DIY/

As advertised, it claims "submicron water filtration performance."

It almost seems too good to be true, that it could be so simple.

If anyone has actually used this product, or has another product they are particularly keen on, I would love to hear all about it!

[Odd Man Out]

That's very interesting. The independent performance test they post tested with live bacteria and virus. I wish they could spell pH correctly though (ug).

This is the manufacturer's web site:

http://www.rapidpure.net/index.asp?pageID=9

Here is another distributor's web site:

http://www.getpreparedstuff.com/category-s/1876.htm

[Oma-n-Opa]

Yes, the manufacturer's link claims it is superior to the Katydin and Sawyer systems, which I have read good things about. I am hyper-alert to the possibility of picking up bugs via water because I am currently in a period of remission from IBS. Certainly don't want anything along those lines rearing its ugly head along the trail. The also have a pretty handy little straw filter system they claim is just as effective.

[Odd Man Out]

The big problem with backpacking filters had always been that they eventually clog (sometimes very quickly) at which point the filter must be replaced, and pumps are slow, heavy, take a lot of work, and are prone to breaking. The Sawyer filters eliminated all of these problems. This rapid pure filter would seem to have most of the advantages of the Sawyer with the added benefit of filtering out viruses (although the degree to which is an advantage in the US is debatable). It would seem they may also have a higher flow rate. The down side it that it is only configured for use as an in-line filter (not much of a disadvantage, really), but most importantly is that it has a limited life span (can't be backflushed) so presumably at some point it will clog and have to be replaced. The cost of the filters and the projected life spans would make that also not so much of a disadvantage, but until we see how they perform in the field, we won't know for sure. Also, they report no information abut freezing the filter (that I saw). For now, I would assume it has the same limitation as the Sawyer. If it were freeze tolerant, that would be a big advantage.

[Starchild]

...but most importantly is that it has a limited life span (can't be backflushed) so presumably at some point it will clog and have to be replaced...

To this point all filters will clog eventually and back-flushing, although it helps somewhat, does not make it non-clog-able. It just opens some more of the filter that was 'covered', and does little to actually remove or dislodge clogs.

[Oma-n-Opa]

I contacted the manufacturer in reference to the question of freeze tolerance, and what their in-use track record is, regarding clogs. Of course they will give me the "rose colored glasses" answer, if they respond at all, but I will let you know what they say if/when I get an answer.

[Oma-n-Opa]

Oh, I almost forgot to say, "Thanks!" for helping me consider issues that had not occurred to me.

[HooKooDooKu]

Sawyer has sub-micro performance.

The MINI and the squeeze are rated to 0.1 micron absolute.

And while not really designed for the back-packer, they also have the "Point ZeroTWO Bucket Purifier Assembly" that also filters virus rated to 0.02 micron absolute.
But I say it's not designed for back-packers is because it is rated for 170 gallons per day (i.e. 7 gallons per hour, or about 10 minutes per gallon... and that assumes you are using the filter in gravity mode with about a 4' head of water before the filter to provide a little water pressure).

Of course what I find interesting is I can not find any reference (at least not with a quick look over of the RapidPure documentation) that suggests they are trying to filter based on sub-micro holes. Instead, they make reference to utilizing electro-mechanical properties to filter bacteria and virus from the water, where-as Sawyer does it strictly based on mechanical filtration.

[Odd Man Out]

Sawyer has sub-micro performance.

The MINI and the squeeze are rated to 0.1 micron absolute.

And while not really designed for the back-packer, they also have the "Point ZeroTWO Bucket Purifier Assembly" that also filters virus rated to 0.02 micron absolute.
But I say it's not designed for back-packers is because it is rated for 170 gallons per day (i.e. 7 gallons per hour, or about 10 minutes per gallon... and that assumes you are using the filter in gravity mode with about a 4' head of water before the filter to provide a little water pressure).

Of course what I find interesting is I can not find any reference (at least not with a quick look over of the RapidPure documentation) that suggests they are trying to filter based on sub-micro holes. Instead, they make reference to utilizing electro-mechanical properties to filter bacteria and virus from the water, where-as Sawyer does it strictly based on mechanical filtration.

I thought the RapidPure site was surprisingly transparent about their technology. Often companies want to obfuscate for proprietary reasons. Yes they are very clear that they have large pore sizes in their filters (which accounts for the high flow rate at low pressure), but utilize this electrostatic filtering mechanism ) which accounts for the ability to filter despite large pore size). They do say that particles are permanently bonded to the filter, but due to the large density of binding sites, they still claim a reasonably high lifetime for the filter.

[Oma-n-Opa]

Here is what was my almost instantaneous response from the founder of RapidPure.

Good afternoon,Thank you for your interest in our RapidPure water filtration products. Regarding your question on clogging. If you have high turbidity or muddy water as your source, we recommend using a coffee type filter upstream to eliminate high sediment build up. Or alternatively, if you use the RapidPure filter use tab water, distilled water, or filtered water to pour over the filter in order to remove high sediment build up.


In regards to your question on freezing. As most filters go, we do not recommend freezing our filter, yet it will not compromise the integrity of the system. Users in the cold climate or ski/snowboard industry who use our Scout inline hydration filtration system have had their filter freeze. This is not an issue, as long as you do not break, squeeze, or drop the filter. What we recommend, is letting the filter thaw so that the media is not compromised and the user can then utilize the filter in the means in which is was designed for: +42F to +120F.


Sorry for the lengthly response, but yes. The filter is freeze tolerant. Does this help answer your question?
Best regards,

Scott Ruprecht
651.302.6004
[email protected]
www.RapidPure.net

[Oma-n-Opa]

That being said, the clogging issue doesn't seem to be that huge. I think it is something that can be dealt with. I don't anticipate using it in freezing weather, as I am moving south and plan to be done with my section before the first freeze, with any luck. Unless someone else can think of some catastrophic incident that could occur that we haven't considered (or has access to factual reports of this device failing and causing disease that I have not come across, scouring the internet), I think I am going to give it a go.

The selling points for me are:
*Price
*Advertised filtering ability
*Advertised quality vs. price
*Ease of Use
*Quick-filtering ability
*Weight/Size
*Customer Service, based on how quickly my e-mail was answered.

I will post a report once I get the device and do a few test runs, and a bit more in-depth report once I've used it on the trail.

[kidchill]

Not to rain on your parade, but it kind of feels like an infomercial...Someone pointed out they couldn't spell pH correctly, and they're right. Maybe not a big deal, unless you're science educated. Also, this whole virus filter situation...well, generally speaking, filters are poor at removing viruses. It's not a design flaw, it's just inherent to the nature of the device. Viruses are really, really small. That MS2-bacteriophage ( I had to google it), but it has a listed size of roughly 25nm or 0.025microns. Now, the saywer squeeze (which I used on my thru without problems) is rated at 0.1microns. So, is the rapid pure better? Well, if you want to rely on some kind of electrostatic charge, and a single test from some lab that you've never heard of, okay, sure. What I do have a problem with is them listing that it removes 99.99999% of viruses. No, it MAY have removed 99.9999% of the MS2-bacteriophage from the water, but that doesn't mean that the other countless number of viruses from a water source will be removed (they may be, and probably are MUCH smaller). It just means it filtered that relative amount for this one test (which we assume was from an independent lab, without bias or financial incentive). The other thing that really bothered me was this whole electrostatic charge (which is permanent {apparently}, and creates a "force field"), and also the whole "atomic level" filtering. Ummm...do I really need to explain how ridiculous this sounds? There's no way in hell that thing is filtering atoms! And last I checked this wasn't Star Wars, so I'm not sure there's any cause to believe force fields are present. Listen, electrostatic forces are the weakest forces in chemistry, so you're gonna tell me a virus passing through is "permanently bonded" to this filter material? I'm sorry, I just don't buy it. Now, in reality, this filter media probably works just fine. It's most likely absolutely more then adequate for you to use. I wouldn't buy it for two reasons. First off, I wouldn't want to collect water in a bucket and then have to siphon it, etc. Second, they're trying too hard to sell it, in a completely weird way. I'm not saying the product won't work, in all honesty I bet it would probably work fine for bacteria, protozoa, as well as spores; however, I do question it's ability to filter viruses and "atoms." But, to each his own. You've already ordered it, so run with it. If anyone asked what I would recommend, it's the Sawyer squeeze with an eye dropper of household bleach in case of failure. The main problem with filter devices is that at some point they may fail.

[hikehunter]

I use the Sawyer system. Never had it freeze, then I empty it as best I can after use. When the filter is nearing the end of its life and I feel the water source is questionable I will boil it. I look at dead microbes a more protein.

[Odd Man Out]

I would say I'm not quite so pessimistic as kidchill. He is correct that we have limited information and in reality we won't have a good handle on how this product performs in the field until someone tries it. As for filtering viruses, with its pore size, we can be fairly confident that the Sawyer is not filtering many (and they don't claim to), thus we can also be confident this new filter isn't any worse. I did point out their misuse of pH, but I also pointed out that they were much more forthcoming with technical information than most companies. I have seen lots of pseudoscience marketing hype and their documentation raises a lot fewer red flags than most. I did a Google Scholar search of pseudoboehmite and found that there have been a ton of research of these materials published in nanotechnology journals in the last few years. A lot of it deals with its cationic adsorption properties. The ability to fabricate these materials at the nanoscale makes the control of interactions at the molecular level feasible. I wouldn't discount the potential effectiveness of electrostatic attraction. It is not the weakest attractive force in chemistry. It has a substantial bond energy. Also adsorpton filters have been around for along time (activated charcoal, e.g.). The ability to fabricate a cationic adsorption filter with a controlled nano-scale pore size would logically give it the high performance characteristics they claim. I would be confident giving this product a try. Also, it is not necessary to collect water in a bucket and siphon. They have a product that is an in-line filter, so it could be used the same way any of the other in-line filters are used. I don't see they claim to be filtering atoms, and a careful reading of their virus claim would seem to accurately represent the lab results which were done with a standard EPA method.

"Bacteriophage MS-2 (ATCC 15597-B1) was used as a model for human viruses. It is of similar shape and size to human enteroviruses and thus is used to determine filter’s viral capture efficacy. It was enumerated using E. coli C3000 (ATCC 15597) as a host using the single layer plaque assay agar procedure as per EPA 1601."

[Gambit McCrae]

I use the Sawyer system. Never had it freeze, then I empty it as best I can after use. When the filter is nearing the end of its life and I feel the water source is questionable I will boil it. I look at dead microbes a more protein.

+1 on sawyer filter

[Mobius]

The explanation of their "electropositive media" to attract viruses and other baddies that would otherwise fit through the filter media makes me want to do more research into the efficacy of such a system. How well does it hold up over time, with dirty water (they suggest pre-filtering which is added complexity and work), with a variety of viruses? I take any claims from any manufacturer with a grain of salt.

They list an actual pore size of 1.75 microns. For comparison Sawyer Mini lists a 0.1 micron capability. A Sawyer with 0.02 is available.

The website does list a link to a report that seems to show that an MS2 Bateriophage (virus) was filtered out when filtered in a lab sample at the rate of half a liter per minute. It's unclear if that rate is required to the "electropositive media" to work. That seems slow to me.

For what it's worth the CDC (who are probably very conservative) recommends <= 1 micron for protozoa and <= 0.3 micron for bacteria. This filter meets neither based on pore size. I remain unconvinced about the attraction making up for the rest.

No filtration is listed as sufficient for viruses - only chemical treatment (with chlorine dioxide, i.e. AquaMira, and chlorine both listed as highly effective). http://www.cdc.gov/healthywater/drin...treatment.html

I'm all for new technology but choose not to experiment with my personal gi-tract.

[Odd Man Out]

The explanation of their "electropositive media" to attract viruses and other baddies that would otherwise fit through the filter media makes me want to do more research into the efficacy of such a system. How well does it hold up over time, with dirty water (they suggest pre-filtering which is added complexity and work), with a variety of viruses? I take any claims from any manufacturer with a grain of salt.

They list an actual pore size of 1.75 microns. For comparison Sawyer Mini lists a 0.1 micron capability. A Sawyer with 0.02 is available.

The website does list a link to a report that seems to show that an MS2 Bateriophage (virus) was filtered out when filtered in a lab sample at the rate of half a liter per minute. It's unclear if that rate is required to the "electropositive media" to work. That seems slow to me.

For what it's worth the CDC (who are probably very conservative) recommends <= 1 micron for protozoa and <= 0.3 micron for bacteria. This filter meets neither based on pore size. I remain unconvinced about the attraction making up for the rest.

No filtration is listed as sufficient for viruses - only chemical treatment (with chlorine dioxide, i.e. AquaMira, and chlorine both listed as highly effective). http://www.cdc.gov/healthywater/drin...treatment.html

I'm all for new technology but choose not to experiment with my personal gi-tract.

Of course this filter does not meet the CDC requirement for pore size because the pore size recommendations are for filters that function by exclusion and this filter is not an exclusion filter. It makes no sense to apply an size exclusion standards to an adsorption filter.

It is will known that cation coagulation and adsorption ARE effective means of virus removal, as are filters with very small pore sizes such as the Sawyer 0.02. It is just that the current systems are not efficient or practical for field use.

Also keep in mind that lots and lots of hikers are drinking water with no protection from viruses (this includes everyone who doesn't treat their water our uses a Sawyer filter). Virus protection really isn't a huge issue for hikers in North America. Also, I don't see that the possibility that other viruses or faster flow rates may result is lower virus filtration rates is particularly relevant. When it comes to the issue of virus filtration, a filter that removed ANY viruses would be better than a Sawyer Mini. If you are choosing between filtering and chemical treatments, then yes that would be an issue. But I am looking considering this filter in how it compares to other filter, especially the Sawyer filters as they seem to be most commonly used.

As for the need to pre filter, any filter will clog sooner with turbid water. Lots of people rig up pre-filters for their Sawyer filters for this reason, so that doesn't necessarily make this filter more deficient than other filters. But Sawyer filters are designed to be backflushed so this may make them better able to handle turbid water.

[kidchill]

[QUOTE=Odd Man Out;1904037] It is not the weakest attractive force in chemistry. It has a substantial bond energy...I don't see they claim to be filtering atoms, and a careful reading of their virus claim would seem to accurately represent the lab results which were done with a standard EPA method.


Well, technically Van Der Waals (probably didn't spell that right) are the weakest bonds, right? That's what I was thinking of when I stated that. They're calling this an "electrostatic" bond..but isn't that ionic bonding? Do you really think this is truly ionic bonding, or as strong as an ionic/electrostatic bond..if that's what they mean? I'm not really sure what the proper terminology is, or exactly what they're trying to say. It sounds much more like a Van Der Waals type of charged bond, which IS extremely weak. "The small size of the AIO(OH) fibers allows RapidPure technology to operate on the atomic level." How do you take this statement? I guess no, it's not technically saying they're filtering at the atomic level, but...I guess it just sounds to me like they're trying to use jargon so people think they have an ATOMIC filter, lol. I'm not trying to be pessimistic, and I haven't read the literature on this type of filtration. I don't really care enough to invest the time. But, just from reading their description, I feel like they may be making it seem like it's the best-est thing ever! Like I said, it probably works quite well, I'm just not sure if it's truly novel. Also, if anything, I'd like to see independent data. "However, this new filter purifier technology outperforms all other recreational water filters with documented Bacteria Removal at 99.9999 %, Virus Removal at 99.9999 %, and Cyst removal at 99.998%. Further, this new filter technology outperforms the competition with higher flow rates, longer filter life, and better affordability. Get that ? This does more for less money !" Sounds like an infomercial. The way they state virus removal is like it does this all the time, with any virus. What's actually documented is a single bacteriophage trial. Further, how do they know it outperforms other filters when there's no data from the other filters? Also, I'm pretty sure Sawyer said it was functional for 1 million gallons. Wasn't this filter significantly less then that? The flow rate may be true, I can't remember what the Sawyer was, it probably wasn't winning any speed contests, but it also didn't feel like I was constantly waiting on water when I did my thru. And doesn't greater flow with membrane/porous filters usually mean the holes are larger? Is that a good thing? I don't know. All I'm really trying to say is, if I went to a water source and was truly worried about viruses, I would boil, chemical, or UV treat the water. Without really reading the lit, I'm just not sure I would trust these "static" forces. On the flip side, my sawyer did freeze in the Smokies and I just kept on using it, lol. So, who knows if it was really doing anything at that point. Half the time, if it was a spring, I wouldn't filter at all. A couple girls called me out on it and I just looked at them and said, "If I get giardia, I'm going home to my bed, running water, TV, and REAL food!" LOL...I was kidding...well, kind of...lol