BackpackGearTest
  Guest - Not logged in 

Reviews > Water Treatment > Filters > Sawyer S1 Select Water Filter > Test Report by joe schaffer

Sawyer S1 Water Filter

Test Report by Joe Schaffer

INITIAL REPORT - October 9, 2021
FIELD REPORT - December 22, 2021
LONG TERM REPORT - February 1, 2022
REVIEWER INFORMATION:
NAME: Joe Schaffer
EMAIL: never2muchstuff(at)yahoo(dot)com
AGE: 73
GENDER: Male
HOME:  Bay Area, California USA

     I enjoy California's central Sierras, camping every month with a goal to match my age in nights out each year. For comfort I lug tent, mattress, chair and such. Typical summer trips run 5-8 days; 40 lb (18 kg), about half food and water related; about 5 miles (8 km) per hiking day in the bright and sunny granite in and around Yosemite. I winter base camp most often at 6,000 to 7,000 ft (1,800 to 2,000 m); 2 to 3 nights; 80 lb (23 kg); a mile or so (1.6 km) on snowshoes and towing a sled.

INITIAL REPORT
Product: pkgcontentsS1 Select Filter

Manufacturer:  Sawyer Products, Inc.
   
    Website: https://www.sawyer.com
Manufacturer description
from website, packaging and included pamphlet:  
    Select S1 is a dual stage filter. Inside the silicone bottle is a foam filter that uses adsorption to remove chemicals and pesticides. The Micro Squeeze Filter on top removes standard pathogens along with any other sediment, particulate, and microplastics. Adsorption filtration is the process in which molecules adhere to the surface of the adsorbent foam membrane. This filtration and purification process, combined with 0.1 micron absolute filter ensures all particulate or pathogens above 0.1 microns are filtered out, including bacteria, protozoa, cysts, dirt and sediment.

        Weight: 10 oz (280 g)
  
        Features:
           
•0.1 Micron absolute filter
            •Removes: 99.99999% of bacteria
                               99.9999% of protozoa and cysts
           
•Reduces: a) pesticides down to 0.01 parts per billion (400 times lower than EPA maximum recommended level
                             b) chemicals down to 0.5 parts per billion (up to 40 times lower than EPA recommended level)
                  
            •Improves taste
            •1,600 +- 20 oz (0.6 L) filter uses

My Specs:
        Weight:
             Bottle when dry: 7 7/8 oz (224 g)
             Filter element when dry: 1 5/8 oz (46 g)
             All parts before any water: 11 oz (311 g)
             Full bottle & filter: 2 lb 3 3/8 oz (1,010 g)
             Bottle only when squeezed out w/out filter:
12 5/8 oz (360 g)
             Bottle only when squeezed out w/filter:
14 7/8 oz (422 g)
             Plunger: 1 oz (26 g)
        Dimensions:
             Bottle length w/filter: 13 5/8 in (34.6 cm)
             Bottle length w/o filter: 11 1/8 in (28.3 cm)
             Bottle width: 2 1/2 x 2 1/2 in (64 x 64 mm)
             Filter: 3 7/8 in x 1 1/2 in diameter (9.8 x 3.8 cm)
             Plunger: 5 3/4 x 1 7/8 in (14.6 x 4.8 cm)

MSRP: on Amazon, US $89.95 claimed as MSRP; offered at US $79.99

Received: 10/5/21

My Description:
    S1 system includes the flexible silicon bottle &
charcoal-infused foam insert, filter, standard cap, flip cap, flush plunger and bottle thread adapter.

    The system provides treated water out of the bottle or into a receiving vessel. The process involves filling the bottle to the prescribed level; squeezing the bottle in an alternating motion for 10 seconds to work the water in and out of the foam; then squeezing the bottle to force water through the Micro Squeeze filter. The silicone bottle and the internal foam are flexible enough to 'wrap' the bottle up from the bottom in order to apply greatest squeezing force.

    S1 offers two ways to backflush the filter. A provided plunger allows a powerful surge through the filter. The included blue adapter allows the output end of the filter to screw onto a typical plastic bottle, and then squeezing the bottle pushes water through the filter. Clean water is required in both cases. The plunger does not interface tightly with the filter's output nipple and relies on contact pressure.

Impressions:
   I have maybe the very earliest iteration of Sawyer inline filter and it's been my sole filtration device on 455 nights of outings. S1 is an innovative water treatment system; haven't seen anything quite like it before. Initial take is that it's weight-competitive and since I do carry a trail bottle, the system effectively could take up no additional space as a replacement for my regular trail bottle.

    Of course I took off the black (reducer) cap immediately because I look at a bottle and feel instantly compelled to peer inside, especially when there is in fact something in there! If a fellow is oriented toward reading directions, then it's clear not to do that. Having done it, the the advice is to re-establish the possibly now-damaged seal, with no instruction as to how to do that. A further caution warns that a damaged or otherwise incomplete seal could allow untreated water to drip (or as I discovered, squirt) into the receiving vessel. When a part can be easily damaged and the damaging act is likely to occur, putting a warning tape on the part might well serve the interests of all concerned.

    The directions are clear enough. I read 'em a half-dozen times to make sure I wouldn't do something wrong again.

    The fill hole (from removing only the little white cap) is too small. Even under the stream of a controlled outlet I couldn't keep from getting spill on the outside of the bottle; and of course any spill on the outside could drip into a receiving vessel. (So I do wonder about the website pic of the bottle being dunked in a stream to fill it.) Water doesn't freely flow in, it has to settle in while the foam absorbs it. The bottle easily overflows as it 'burps' air and can take a minute or so to fill.
Holding the bottle up to look for the line (which I find difficult to see) compresses the bottle, raising the water level. Setting it on the counter relaxes the bottle, lowering the water level.

    The correctly-full bottle & filter weigh
35.6 oz (1,010 g). (If I'm using it as a trail bottle, the filter has to be attached.) Squeezing it out I managed to get the weight down to about 17 oz (480 gm).  Do I want to carry over 2 lb (0.9 kg) of water bottle that has a little over a pound (0.45 kg) of accessible water in it? (Pack weight doesn't care if the filter is on the bottle or in a pack pocket, so the filter part of that weight has to happen either way.) If I still have to carry my regular trail bottle, then the S1 bottle becomes 3/4 lb (350 g) additional baggage. (I can squeeze more water out with the filter off.)

    Even for me
it's difficult to put the Micro Squeeze filter on backwards, but with the blue adapter, not impossible. Some kind of direction indicator on the filter would be helpful, especially for backflushing.

    Squeezing out two rations made my arthritic fingers hurt so much I couldn't twiddle them the rest of the day. Directions suggest being able to yield about 20-22 oz (0.6-0.65 L). I couldn't quite manage the low end. I also noted on the white sink what appeared to be charcoal dust from backflushing the filter, which I assumed (incorrectly) to be loose charcoal coming from the filter, a not uncommon circumstance with new filters.

    I need 4-5 L (qts) a day. With my trail partner we'll need a few more. When no fires allowed, that means 6-7 L (qts) or so per day a little better than 0.5 L (pint) at a time = something in the order of a dozen cycles. That's a lot of filling and squeezing. And can I do that without messing a drop of untreated water into the receiving vessel?  I can't keep faucet-drawn water off the bottle, I cannot imagine how that will be accomplished teetering at the edge of a stream. The product is surely not intended for tandems, but even solo, I don't see it as a practical exclusive water system.

    Website says the Micro Squeeze filter (presumably the same one) is good for a buzzillion gallons; package says the system is good for 1,600 uses, which at say, the top end of 22 oz (0.65 L) each would be about 1,100 qts (1,000 L). If use averages 3 qts
(L) a day it would take about 330 days--five to six years at my current average--to use it up. I don't find any instruction or indication to know how to determine the system is exhausted. As the Micro Squeeze filter can be purchased separately, presumably Sawyer's S1 calculation applies to the bottle and/or innards. I don't find any reference regarding a replacement bottle or charcoal pack.
   
    W
ebsite general descriptions of the S1 & S3 models appear to remove all of the same pathogens. A deeper plunge into the stats reveals a key difference: Evidently S1 does not (and S3 does) remove viruses and heavy metals.
carbon
    Directions indicate flushing the bottle should require only a half-full bottle one time, without the filter. After that and then two full bottle attempts and two filter backflushes; the Eureka moment finally struck that perhaps the stubbornness of the Micro Squeeze filter must be related to charcoal going into it and not from it. I flushed the bottle eight more times without the filter. Even after that, the filter still clogged up before it passed barely enough water to backflush it.

    It fin
ally also sunk in to test the Micro Squeeze alone, at home, before relying on it in the woods. The filter's gravity flow rate is (at least for the test L/qt of tap water) satisfactory.

    Using Sawyer's online customer service form
I inquired as to whether the bottle innards might somehow be not working as intended as after 10 1/2 flushes it is still releasing easily visible amounts of charcoal. (Photo shows result of last 8 full-bottle flushes; recovered and dried powder weighed a gram (1/28th oz), about half-a-teaspoon.) That contact was not successful, but the test monitor suggested persistence in fidelity to BGT test procedure. Directly sending an email established several timely exchanges ultimately resulting in a return and replacement system.

SUMMATION: Not easy to fill; hard for me to squeeze; would be relatively heavy in use; clogged immediately.

Quick shots:
    a) No hanging
    b) No pumping
    c) No chemicals to add
    d) 10 seconds waiting & squeezing to prepare for filtering
    e) $ competitive system

    f) Heavy when in use
    g) Bulky to use
    h)
Too much squeezing
    i)
Not practical as a lone water system
    j) "Grabby" surface on bottle
    k)
Clogged with charcoal.

Field Conditions:
   
1. Oct 13-18, 2021:
Emigrant Wilderness, California. 5 nights, 14 mi (22 km) trail + 3 mi (5 km) XC; leave weight 43 lb (20 kg), return 37 lb (17 kg); 32-60 F (0-16 C); 6,000-8,000 ft (1,800-2,400 m); 4 camps. 2 days algae-stained water; 4 days clear water; 2 persons.
   
2. Nov 2-5, 2021: Emigrant Wilderness, California. 3 nights, 13 mi (21 km); leave weight 43 lb (20 kg), return 39 lb (18 kg); 32-50 F (0-10 C); 7,200-9,200 ft (2,200-2,800 m); 3 camps. Clear snow-melt; 1 person.

Impressions:
gravity
    As a gravity filter the Micro Squeeze met two people's total hydration needs for six days. It did require backflushing once or twice a day; and doesn't go faster than a trickle even when freshly flushed. Of course the higher the source hangs, the faster the flow. I never had occasion to time it. It is certainly not speedy; though I have another similar type that is no faster; and also the previously referenced Sawyer product that is faster. Micro works fine in camp while I'm doing other chores. The time required to refill a trail bottle makes it not practical during a hike. (Perhaps worthy to note that the older Sawyer drip/inline filter while being faster and so far never having required field-flushing, does not fully remove algae stain.)

    The Micro Squeeze filters out algae stain, where source water is about the color of light tea.
A spring where we normally get clear water was drought-tortured to a stagnant puddle laden with loose algae and copious debris. Straining through eight layers of paint screen removed all visible detritus except the stain. Filtered water came out clear; and backflushed water started brown. The filter would handle about a 2-3 L/qts before dripping so slowly as to require backflushing. With clear water that was available at lake sources the filter would manage about twice that before choking to an intolerably slow drip.

    I don't know what the unfiltered water would taste like. I didn't notice any taste or odor to the output; nor did my partner.

    The wet filter weighs 60 g (2.1 oz). It's roughly the size of a more oblong chicken egg--very small for a water filter. Because of the backflushing frequency necessity, relying on the filter requires carrying the included plunger, adding 26 g (1 oz) in weight and roughly 1 1/2 times as much bulk. Contact pressure alone will not make a tight seal between plunger and filter, meaning the hand holding the two together gets wet. This would be a meaningless nit on those days I carp about being too hot, but at near freezing temps the drenching takes on a different aspect. A dedicated short length of tubing or switching out the output hose would resolve that, but either nudges the fiddle needle toward the red zone. Two squirts through the filter seem to reach the maximum flush--maybe even one would do it. After the first half-plunger I don't observe dirty water squirting out.

    Small has many advantages; not the least of which is taking up minimal space in a pocket to keep the device from freezing. Website advises that freezing can harm the filter (so far as I know the case for almost all backpacking filters). CS replied the S1 bottle may freeze without damage. The bottle would have to thaw out before use, but at least it doesn't have to go in the sleeping bag on chilly nights. I will not be able to hike with the bottle in now sub-freezing Sierra temperatures as I won't have a way to keep it warm enough--big and 'grabby' to have flopping around under my jacket. I don't know how cold temperatures would have to be and/or exposure time to cause a freeze-up. I have been on hikes where my trail bottle froze enough I couldn't get water from it.

     M
y priority for water treatment is straining out cysts, protozoa and bacteria; namely crypto, giardia and E.coli. The vendor's claim of 0.1 microns for the Micro catches those bugs. Were I inclined toward squeeze bottles it should be possible to extricate the bottle innards, eliminating any possibility of charcoal clogging; as well as making the bottle easier to fill.

    On a 'warm' December trip I had hoped to try the bottle, but its replacement was still in the ether. One morning on a 9,200 ft (2,800 m) ridge top greeted the day with bracing blasts of icy sprites and I huddled in the tent to pack up as I wolfed morning gruel. The snow-melt I had was clear, drawn from a small, slowly seeping puddle. Outside was too harsh to hang the drip filter I had with me or to have campfire for boiling.
Chemical treatments simply will not go down and I no longer carry any. And I'd apparently rather risk bugs than exhaust an emergency ration of stove fuel to bring ice water to boil. As I engaged the risk of wild water a benefit of the S1 system became more apparent--it should be pretty easy to use in a tent.

Quick shots:
    FILTER:
    a) Small
    b) Light
    c) Removes even algae stain
    d) Not rapid
    e) Requires frequent backflushing


REPLACEMENT S1 SYSTEM received 12/9/21

    System
2ndS1arrived with the bottle's reducer (black) cap barely engaging the bottle's threads, not in tempo with instructions to avoid loosening the cap.

     I took great care to ensure I was following directions, (causing a level of stress possibly affecting procedure); excepting the Micro was not involved this time. The first flush resulted in a barely visible release of charcoal. A second revealed a little more. To keep things comparable, I dumped the first two flushes and started again with the third, continuing through a tenth. The replacement bottle expelled a visibly comparable accumulation of charcoal, though the recovered amount this time did not register a gram (1/28th oz).

   
Is the replacement defective as well; or is neither and such expulsions to be expected? The possibility of user error must be accounted, but if that's it, then the system is too complex for me and/or too vulnerable to misuse.


   
Replacement bottle follow-up 12/28/21: Sawyer CS replied to my email that some bottles require more attention than others, but that no recent purchasers have reported issues with charcoal clogging. They suggested I repeat the directions to see if that would clear it up. I indicated any future use of the bottle would more likely be without the innards; and CS advised the Micro alone "will filter out all the harmful bacteria, protozoa and cysts".
11 to 18
    I flushed another eight bottles of water into the test receptacle. Charcoal accumulation was significantly less, though still more than enough for chronic Micro clogging. Granting that my experience could well be an anomaly, my testing of the bottle--which has not made it to the field--is brought to an early conclusion.


Long Term Report
Micro Squeeze

Field Conditions:
    1. Jan 16-18, 2022: Stanislaus National Forest, California. 2 nights, 3 mi (5 km); pack & sled weight 85 lb (38 kg); 7,000 ft (2,100 m); Clear and calm, 45-20 F (7 to -7 C); 1 camp; campfire-melted snow; 1 person.

Impressions:
   
Chilly weather always presents a water treatment challenge. I'm happy enough these days to sit in one camp and keep a fire going from sundown until bedtime. I usually have time to melt snow to a boil. Sometimes boiling water is not preferred; and/or stove fuel needs to be rationed if I've not towed in enough firewood. In such circumstances, a filter works better and the Micro is just the ticket. I do have to remember to get it (as with any filter I have) back in a pocket as soon as no more water is going through it lest it suffer the risk of freeze-damage. Micro's tiny profile makes it barely noticeable in a jacket pocket or foot of a sleeping bag. 

Summary:
Requires frequent backflushing, but is tiny, light and works great in camp.


BOTTLE: I removed the charcoal pack and carried the bottle with only water in it.

    I find it not easy to tell which side of the pop top to flip up. When on the correct spot, the top pops up easily enough, but with no innards, the bottle is too willing to collapse. Just holding onto it compresses the bottle and squirts water out before I expect it. I confess to getting a little grumpy at dousing myself each time I wanted a drink and was glad the temperature was warm enough that I dried out. Attaching the filter mitigates unanticipated ejections.

    In fiddling around to get the pop top flipped, the black reducer cap comes loose rather easily, enough to leak. One might guess the result of squeezing the bottle tightly enough to get the cap again fastened or even to snap the pop top back down.

   The longer apparatus proved a challenge. Though some people would say the target is more than large enough in my case, conscious effort was required to hit the sweet spot and not the surrounding area. Pulling my sled gets me to huffing and puffing and evidently saps the incremental energy required to assure accurate placement.

    The bottle is slow to take water as it easily air locks. Removing the mouth screen behind the reducer cap opens the bottle for faster filling, but it does need to be replaced as part of the bottle's limp structure. It's not that difficult a task, though snowmelt is cold to start with, and when temps are low, the water that easily disgorges is not a welcome accessory to one's hands.


Bottle Summary: The charcoal pack-less bottle works very much like a squeeze bag. I found its limpness clumsy and impractical as a trail bottle in particular, but even as a camp bottle difficult to handle without splashing water around.

Thank you Sawyer and BackpackGearTest.org for the opportunity to test this product. Testing is concluded.



Read more reviews of Sawyer Products gear
Read more gear reviews by joe schaffer

Reviews > Water Treatment > Filters > Sawyer S1 Select Water Filter > Test Report by joe schaffer



Product tested and reviewed in each Formal Test Report has been provided free of charge by the manufacturer to BackpackGearTest.org. Upon completion of the Test Series the writer is permitted to keep the product. Owner Reviews are based on product owned by the reviewer personally unless otherwise noted.



All material on this site is the exclusive property of BackpackGearTest.org.
BackpackGearTest software copyright David Anderson