ultralight water prefilter

[Ken Larson]

Information that might aid in the making of the pre filter discussed above.

Modified Gator Aid Cap and Nalgene Cap showing the mesh epxoxied within. You must leave a lip of the original plastic around the inside of the cap for the mesh to rest on and for the epoxy to adhere to.

Nalgene Cap

Gator Aid Cap

Gold Tone Coffee Filter mesh size is 3 microns (Source: Krups Consumer Service)

[Matthew Swierkowski]

@Ken

Ahhhh…so it's glued in there. I got the impression that it was somehow just press fit in there. Ok, I actually left a lip on the cap I was working with so gluing in a piece of screen would be no big deal. Now the million dollar question…what glue to use? You mention epoxy, does that work and what epoxy did you use?

I was working on a much more complicated pre-filter than the one in this thread when I came on this thread, and per my research there are not many adhesives that stick to polyethylene or polypropylene (the materials most of these bottles and caps are made of). The only thing I found that works is the Loctite Plastic Bonding System (consists of an activator and super glue). I suppose another potential option would be to melt the screen into the plastic with a soldering iron. Anyone tried that?

[Brendan Swihart]

are the metal screens you guys are using fine enough to prefilter silty/turbid water for use with a steripen? For convenience sake or if you're just trying to get out floaties the fine mesh seems great but if you're trying dealing with more murky water it seems like paper filters would be better??? I have an opti on the way and some places I frequent the water can have lots of clay so I'm wondering what a good setup will be.

[Jerry Adams]

Those filters are for sticks and leaves and things

No filter is good for silt

Even pump or gravity filters aren't that great for silt – they'll plug up for one thing

I fill my 4 liter Platypus, and then the next morning most of the silt is on the bottom, just don't agitate the bottle and pour off the top.

To treat turbid water, the instructions say to double treat

[Kattt]

A 4" x4" piece of cheese cloth, folded twice, to make four layers. Works much better
(faster) than a bandanna and seems to catch a certain amount of silt too.

[Ken Larson]

Matt……“You mention epoxy, does that work and what epoxy did you use?”

>>>>>GORILLA. The Glue Guide by Gorilla does state, “Bonds most plastics, but not polyethylene or polypropylene as you had mentioned.” I have had no issues to date with the caps and as long as the adhesive holds the screen in place without fall out (my purpose) the cap pressure will do the rest.

Brenda…..“are the metal screens you guys are using fine enough to prefilter slit/turbid water for use with a steripen."

>>>>>I use my prefilters with my SteriPen when needed and that has not been that often as I am VERY SELECTIVE when it comes to the amount of dissolved and suspended solids in the water source I take my water from due to my suppressed immune system. When I use my Larson Designed Gravity System (Sea To Summit 8 liter Ultra-Sil Dry Sack, 5 micron (nominal) pre filter sewn into the bag, Sawyer .02 purifier) with my grandchildren I have also no issues and produce water in large amounts (Average 290 sec/liter) quickly when I suspend 1.5 gal at a time.
Prior to using a pre filter with the Larson Designed Gravity System, I had one big issue in it early testing with Lake Michigan Water in early Spring around South Manitou Island using water that had large amounts of suspended Cladophora algae that you could observe (a native algae species that washes up on the beaches when wind-driven waves rip it off the bottom of the lake and becoming a big issue for the ecology of the lake.) in the water. With my updating of the system I have had great success with many different water sources and “suspended solids” contained within.

Jerry…… “Even pump or gravity filters aren't that great for silt – they'll plug up for one thing”

>>>>> I had a silt issue at Lake Desor (North) on Isle Royale back when I was using a Katadyn Pocket filter (HEAVY, 0.2 micron ceramic filter (cleanable) without pre filtering the water on year, but I quickly corrected this by scrubbing the ceramic filter. (The suspended solids were so fine you could not discern with the naked eye. This island also had Cyanobacteria (Blue green algae) issues in the late summer and closes several inland lakes to the potential health risk to people who are exposed to certain species that contain a toxin. In this case if you see “blooms” or “scum’s on the water you are drawing from…..be conservative and do not use the water. People with other filtering device that used these waters were not so lucky, as thier filters clogged and could not be cleaned.)

Katharina…. “A 4" x4" piece of cheese cloth, folded twice, to make four layers. Works much better
(faster) than a bandanna and seems to catch a certain amount of silt too.”

>>>>This information may interest you:

Back in the lab I tested “grubby bayou” (Late Summer water in front of my house that is a good sampling source for these test.) water through various pre filter materials to determine what material makes the best pre filter. This is what I found out:
1. paper coffee filter – water very clear (as tap), filter rate very slow
2. cloth coffee filter – water tinge of yellow, filter rate slow
3. pelon material – water slight tinge of yellow, filter rate very fast
4. handkerchief – water tinge of yellow, filter rate slow
5. heavily used MSR towel (PackTowl® Ultralite) – water clear, filter rate fast
6. lightly used MSR towel (PackTowl® Ultralite) – water clear, filter rate medium
7. MSR towel (Nano™ Towel) – water clear, filter rate medium fast

CONCLUSION: The use of either the MSR towel (PackTowl® Ultralite or MSR towel (Nano™ Towel) would be the best pre filter material prior to UV, filtering, or purifying water with suspended solids (e.g. algae, bugs and floating debris.) Each of MSR pre filter materials can be washed in the field and used again and had has sufficient surface area to handle most filtering/purifying pre filtering needs. The use of a strong rubber band would aid in affixing the pre filtering material in place around a pot or liter btl/canteen so to enlarge the filter area.

NOTE: The QUALITATIVE nature of the water clarity is based on sight comparison to tap water or water that has been place through a paper coffee filter.

[Roleigh Martin]

http://www.dudadiesel.com/choose_item.php?id=PESP3S

About $3

I've used this for 2-3 years now. Fantastic. Take a wire clipper and clip cut the steel ring, and use a needle nose to remove it, and the remaining filter folds flat and is 1 oz. It is a one micron filter too!

[Link .]

+1 Roleigh, I purchased from Dudadiesel a couple of years ago after reading your post and have been very happy with it.

[Brendan Swihart]

good info Ken and Roleigh. How is the flow rate through those diesel filters? Looking around a bit it looks like a paper coffee filter is between 15 and 30 microns for reference so 1 micron would be pretty awesome if it allowed water through relatively fast.

[Ken Larson]

I have incorportated this filter material in my gravity system describe above. (You can go as low as 1 micron (nominal).

Global Filter, LLC

Standard Mesh Liquid Filter Bags. I believe the specifications of a bag and material I'm looking at are as follows:

Type Fiber – NMO
Micron Rating – 5
Bag Finish – Plain
Bag Size – 1
Bag Style – PESS

http://www.globalfiltercorp.com/StandardMeshLiquidBags.html

Terry Younggreen
Vice President of Operations

7201 Mt. Vernon Rd SE
Cedar Rapids, IA 52403

toll free: 1-877-603-1003
ph: 319-743-0110
fx: 319-743-0220

Email: [email protected]

[Rick Dreher]

Hi Ken,

Wonderful roundup of filteration fabrics. I confess I had to look up "pelon" and the closest I can find is "pellon" facing as used in sewing. Is that the stuff?

So you suppose the pack towel fabric works so well because it's highly hydrophilic?

Thanks again,

Rick

[Ken Larson]

Brendan………The 5 micron bag I described used with my gravity filter works as good as any pre filter I have tested. NO ISSUES.

"Looking around a bit it looks like a paper coffee filter is between 15 and 30 microns for reference so 1 micron would be pretty awesome if it allowed water through relatively fast."

>>>>>That is a correct statement for the 5 micron and I bet it is likewise for the 1 micron.

[Roleigh Martin]

Thanks Anna. Glad this thread came up. I thought prior to today that using a 1 micron pre-filter along with Chlorine Dioxide tablets (but only waiting 20" after use of tabs), that filtering mountain water would be just fine to use as the items you needed to wait 2-4 hours for with the tablets had sizes greater than 1 micron. But then I saw this today: http://www.usbr.gov/pmts/water/media/pdfs/Crypto.pdf

"B. Source in Nature: Crypto and giardia are naturally occurring in the intestines of most mammals, including humans. The highly contagious and infectious form, as found in water, is a hard-shelled cyst in the case of giardia, about 5-8 microns in diameter; and an oocyst for crypto, about 3-5 microns (which is pliable and capable of folding to 1 micron)."

I did not know giardia could be as small as 1 micron.

I've used the pre-filter in 3 situations:

a. pre-filter for steripen to rid water of any crud (by the way, steripen's own technical literature says it does not purify a wolf parasite eggs which are too big for the steripen to handle, but the pre-filter will take care of that).

b. pre-filter for chlorine dioxide tablets (on my JMT hikes, I use the Steripen during the day as the water tastes better that way, but at night, I'm so tired, and water is mostly for cooking, and I use the chlorine dioxide tablets, and wait only about 30" afterwards). In both situations, I use the 1 micron pre-filter.

c. as a pre-filter for a .1 micron sawyer gravity water filter on the superior hiking trail which afterwards I then use chlorine dioxide tablets (to handle viruses).
The pre-filter helps enable me to go more days before the sawyer gravity filter gets too plugged up and needs backflushing.

[Roleigh Martin]

Brendan, the flow rate is so fast, it's like a filter is not involved. It's only 1 micron, not something really, really small like .1 micron. I think it is also fast because it is such a large filter and can handle a lot of volume.

[Roleigh Martin]

Ken, what is the part number of your 1 micron (absolute) filter equivalent to the one I showed from Dudadiesel. What do you mean by "absolute". You'll note the wording by DudaDiesel:

"This fabric does not produce an absolute filtration but rather a range based on generally accepted industry tests. Mandy factors influence the actual filtration including the shape, size, consistancy and loading of the contaminates. Also, the feed pressure and rate of flow affects the filtration results. "

http://www.dudadiesel.com/choose_item.php?id=PESP3S

Last, what is the pricing information and minimum qty order you'll take?

The Dudadiesel bag has these characteristics:
Polyester Filter Bag
• Size#3, with hanging strap
• 8" Length, 4" Diameter
• Singed for prevention of fiber breaking
1 micron (with above caveats)

[Ken Larson]

Rick….“I confess I had to look up "pelon" and the closest I can find is "pellon" facing as used in sewing. Is that the stuff?”

>>>>>YEP, my wife and I sews a lot and I thought I would give it a try.

“So you suppose the pack towel fabric works so well because it's highly hydrophilic?”

>>>>>>That’s my guess and why I tried them.

Roleigh….“pre-filter for steripen to rid water of any crud (by the way, steripen's own technical literature says it does not purify a wolf parasite eggs which are too big for the steripen to handle, but the pre-filter will take care of that).”

>>>>>+1 The bottom line is BOILING OR FILTERING your water will remove the 25 micron hydatid organism threat of the tapeworm.

The use of chemical or UV treatment to remove the bacteria (0.3 – 1 micron), protozoa (3 – 20 micron) and virus (0.01 micron) will NOT remove or eliminate the hydatid tapeworms threat. If you are using chemical or UV treatment for your water, PRE FILTER with a filter that will remove 25 micron size particles…(eg. Diesel fuel filtering material 1- 10 micron, http://www.dudadiesel.com/search.php?query=filter+bags, KRUPS – Gold Tone Coffee Filter 3 micron, handkerchief, MSR towels, paper coffee filters 5-15 micron)to remove the hydatid organism.

[Roleigh Martin]

Ken, when you state the micron range for Dudadiesel, that is for the range of all of their filters. They sell pre-filters that average 1 micron, others that are 5 micron, and others with less filtering ability. The pre-filter I showed is labeled a 1 micron filter, but with the caveats I mentioned, which is why I'm interested in knowing about your pre-filters, if you have one that is absolute 1 micron pre-filter, I want to know how to order it.

As I mentioned, I use the pre-filter always in conjunction with something else (either steripen, chlorine dioxide tablets, or combo sawyer .1 micron filter and chlorine dioxide tablets)).

[Ken Larson]

Roleigh….“ what is the part number of your 1 micron (absolute) filter equivalent to the one I showed from Dudadiesel.”

>>>>>NO, Global Filter, Part # is just the description below for their Standard Mesh Liquid Bag .
Type Fiber – NMO (Nylon Monofilament)
Micron Rating – 1 (micro rating ranges from 1 – 1500)
Bag Finish – Plain
Bag Size – 1
Bag Style – PESS

The bag you have from Dudadiesel has its emphasis in “supplies for SVO, biodiesel, solar water heater technology and will soon also push for solar electrical cells (PV cells), wind power, geothermal systems and energy efficient devices such as LED lights and systems which recycle heat.”

Global Filters has its emphasis in “High Purity Pleated Filter Cartridges for liquid filtration in a variety of Industries including: Food & Beverage, Pharmaceutical, Enzyme, Ethanol, Electronics, Water Service, Reverse Osmosis Pre-filters, Chemical, Petro-Chemicals, Refining, Cosmetics, Ink/Paint.

“What do you mean by "absolute"?”
>>>>> My mistake! Thanks for catching that. It should read:
A NOMINAL rating is attached to filters that can be shown under controlled conditions to remove an acceptable statistical amount of particles of a certain size, even though the actual pores or openings of the filter may be much larger that the particles being removed. The typical way that a nominal filter rating is reported would be in the form of a statement such as: “Removes >99.9% of particles 3μm (micron) or larger.” This means that under field conditions, a user can be confident that the filter will remove greater than 99.9% of pathogenic organisms larger than 3 μm. This information is obtained by challenging filters with test waters containing suspensions of 3μm spheres. A similar cryptosporidium or giardia claim would require a challenge using live cryptosporidium or giardia organisms. Nominal ratings are usually applied to depth filters.

An ABSOLUTE rating can only be applied to a filter that the end user can actually determine the size of the largest pore. Such a filter can be integrity tested using a non-destructive test method and the data can be used to determine the actual size of the largest pore. Absolute ratings can only be applied to membrane filters (see definition below) due to the requirement of a definable pore. If a filter manufacturer applies an absolute rating to a filter, they should be able to provide the user with a non-destructive test protocol that will allow the user to verify the absolute rating.

“Ken, when you state the micron range for Dudadiesel, that is for the range of all of their filters. They sell pre-filters that average 1 micron, others that are 5 micron, and others with less filtering ability.”

>>>>> “micron range for Dudadiesel” above should read micron range for Global Filters do range from 1 – 1500 microns in their Standard Mesh Liquid Bag Models….they have other models not applicable to this discussion. http://www.globalfiltercorp.com/StandardMeshLiquidBags.html

“As I mentioned, I use the pre-filter always in conjunction with something else (either steripen, chlorine dioxide tablets, or combo sawyer .1 micron filter and chlorine dioxide tablets)).”
>>>>>Likewise, I prefilter and us UV or a .02 micron Sawyer PURIFIER.

[Roleigh Martin]

Ken, I'm confused, are you saying a Dudadiesel filter that has a nominal 1 micron rating is inferior to your filter with a 1-1000 micron rating, just because your filter is specifically targeted to drinkable liquids as opposed to biodiesal fuel use?

Don't you have a filter almost identical to the one I showed from Dudadiesel, your pictures show filters that look almost identical?

[Laurence Beck]

Roleigh, How do you use this Dudadiesal filter? I normally backpack in the Sierras and I carry XiniX Klear Water liguid chlorine dioxide treatment. A 1 ml drop treats one quart in 15 mins for Giardia. I would be interested in a pre-filter only for the ascetic value of removing floaties and silt. Do you hang this filter and pour through it or, do you rubber band it across the mouth of your clean water receptacle?

One thing about XiniX Klear Water is that you can treat a larger quantity of water if you let it sit overnight. This is one way that I use it to conserve on Klear Water.

Larry

[Ken Larson]

Roleigh…."Ken, I'm confused, are you saying a Dudadiesel filter that has a nominal 1 micron rating is inferior to your filter with a 1-1000 micron rating, just because your filter is specifically targeted to drinkable liquids as opposed to biodiesal fuel use?"

>>>>>I am not saying that at all. Micron rating are micron rating weather used for diesel or water. Global Filters have a wide range of filtering application compare to Dudadiesel as I see it.

[Roleigh Martin]

Larry,

I bring along two 1.8 oz twist-n-lock ziplock quart containers, one is labeled "dirty" and the other "clean". I scoop up dirty water with the dirty container, and pour the dirty water into the dudadiesel filter into the clean container. The clean container is then steripen'd or else poured into a 2 qt platypus container (with a 1" cap neck). I repeat this twice for the platypus container, then I put in 2 chlorine dioxide tablets in that platypus, put the 1" lid back on the platypus, wait 1/2 hour, and the water is useable for camp in the evening.

I have done beta testing for Steripen and got confirmation from Steripen's support that it will work just fine with the twist-n-lock ziplock quarter container with the caveat that due to UV radiation, the containers are not long term containers. I replace them every 2 years or sooner. I only bring one lid with me, for the clean container, which is kept inside the dirty container when hiking/packing.

I do not use a Nalgene bottle, weighs about the same as 4 of the ziplock containers.

Roleigh

[Roleigh Martin]

Ken, can't you just post a link or part number of the closest competing filter to the DudaDiesel filter I linked to, provide a photo of it, and ordering information, along with technical specs? Thanks!

[Roleigh Martin]

Larry, I forgot to answer your other question. I hang the filter on the top of my pack to dry out between water stops. I squeeze it dry first. If I ever put the prefilter in my pack, I put it in a ziplock freezer quart bag. Overnight at camp, I hang it from a branch to air out.

[Roleigh Martin]

Ken, I'm sorry, I thought you worked for Global Filter. Never mind my request.

[Author]

Posts