Building a Super Sawyer Squeeze Water Filter System, by Pretty in a Blue State

Tuesday, Nov 20, 2012

The Sawyer Squeeze filter has become very popular with backpackers. The filter threads onto a variety of soft-sided bottles and hydration packs. By squeezing a bottle or bladder of dirty water you generate the pressure to push the water thru the hollow fiber filter. Here’s one review.

The biggest advantage of the Sawyer Squeeze filter is that it does not require a pump. This removes the potential mechanical failure of a pump and the hassle of tubing as you balance on the edge of a stream or lake. Just scoop up water, pour it into a bladder, and filter it elsewhere. Other benefits are the small size and light weight. 

It filters faster than many other designs (about one minute per liter) and can also be used as a gravity or in-line filter. It is very simple to back-flush. It is rated for 0.1 microns and is effective for bacteria and protozoa.  It is not rated to remove viruses – so if that is a concern in your area then many other treatments will be more effective after the suspended organic solids have been filtered.

Note that the Sawyer Squeeze filter does not include an activated charcoal element to remove dissolved chemicals. You can add an in-line activated charcoal filter, available from Katadyn or Platypus or you can make your own if you have any concern about chemicals or taste.

Sawyer guarantees this filter for one million gallons. Just for fun, let’s say their claim is only 5% correct – that’s still 50,000 gallons. For 4 people this equals one gallon per person per day for 34 years. 

A shortcoming of the Sawyer Squeeze system is the included mylar bladders for dirty water. They are more prone to leaking than other brands. (The kit comes with three bladders, I’m carrying one as a free backup). A bladder or bottle will require flowing water or some type of a cup to fill with dirty water.

I’ve adapted the Sawyer Squeeze filter to plug directly into a Camelbak Hydrolink bladder in my backpack for quick and easy “on the go” refills and have a system for backflushing without using the syringe included with the filter. My approach also adds a pre-filter as well as protection from cross-contamination.  With so much flexibility I’m going to be listing a lot of options along the way.  Make the system work best for your needs.

Reminder: You should always have more than one way to treat water – I carry Katadyn tablets separately from the filter kit. And protect all filters from being dropped or frozen.

Here’s what I purchased and how I built my system:

1. Sawyer Squeeze Filterthe latest packaging includes a gray dirty water end adapter cap which has a semi-permanent cap on the hose barb. Includes a 60cc syringe for back flushing, 3 mylar bladders, and sport-style pop up drink cap. 

You may need to purchase a Sawyer adapter set. If your Sawyer did not come with the gray male adapter you will need to buy one to seal the dirty water end so that water doesn’t drain out in that direction when you disconnect the dirty water bladder. You will also need a thread protector cap from the hardware store. Buy one with a tight fit. The included blue female cap can be connected by tubing to almost any filter to turn it into a “Squeeze” filter – I recommend having this ability. If you have another filter system you prefer, at least get this adapter and a bladder as a backup to your pump.

2. Platypus or EverNew water bladder. Replace the Sawyer dirty water bladders with a stronger design. Platypus water bladders fit the Sawyer Squeeze (others have written the Soft Bottle style are harder to seal without replacing the Sawyer white washer with a thinner washer). EverNew bladders are described as more durable but they are difficult to find.  I am using the 2 liter Platypus Hoser bladder with a replacement solid cap.

Because there is the chance of confusion, label the bladders you’re using for dirty or clean water and don’t mix them up. And make sure the dirty water end fittings are tight and don’t leak contaminated water onto the clean end of the filter or clean water containers.

Pour dirty water into a bladder or bottle using a cup, a folding bowl, or one of the smaller Sawyer bladders with the top cut off. Still another useful idea is to use a flexible plastic cutting “board” to make a small funnel that will store flat. Or use a small silicone funnel that is sold in some kitchen supply stores. A funnel will double as a bladder filling scoop if you put a finger over the bottom. Don’t reuse a dirty water cup or bowl for eating or drinking.

3. Aquamira Frontier Pro water filter. I use the male/female pre-filter adapter which adds a thick felt pre-filter.  The Frontier Pro includes a Universal Quick Connect (UQC) which you might use on Camelbak or Source hydration systems. It includes 4 felt pre-filters. The Frontier Pro with chlorine dioxide tablets could be a lightweight backup to the Sawyer Squeeze.

A home-built replacement for the Frontier Pro pre-filter adapter can be made from the threaded top to a SmartWater bottle and cap (the threads and caps on the SmartWater bottles fit the Sawyer filter and are sold in many grocery stores – they seem more durable than other brands and are cheaper than the Platypus replacement caps).  Cut the bottle at the top of the neck under the solid plastic ring. Level out the cut on the bottle piece down to the ring with a razor knife and use sandpaper to roughen the surface. Sand the top of the cap and drill a ½” hole in the cap. Use plastic epoxy to attach the pieces.

The closest replacement for the Frontier Pro felt disks that I’ve found is a few layers of the synthetic chamois sold at Home Depot. The felt disks will be placed in the cavity of the bottle thread portion.

Pre-filters will slow the volume of filtered water, but will reduce the sediment getting into the filter and let you filter more water before having to back flush it.

If you want to add an additional pre-filter element you can trim down a Mr. Coffee permanent coffee filter (made of stainless steel mesh) with scissors into disks to fit inside the pre-filter adapter above the felt disk (or below the white washer in the Sawyer dirty water end if you don’t have the pre-filter adapter). The mesh filter is better in the pre-filter adapter for quick removal and backflushing.

Another way to easily minimize large particulates from getting into the dirty water bladder in the first place is to use a woman’s nylon footie (usually sold in a mini-egg container at drug stores) over the bladder mouth when filling.

4. Two bottle or bladder caps. Use 1- or 1.5-liter SmartWater bottle caps or Platypus closure caps to make a double-female fitting. Take two caps and sand the tops to make a rough surface. Use plastic epoxy and press the 2 caps together back to back. Once cured, drill a 1/2 inch hole in the caps.

These caps are also a little too tall to screw down to a tight seal on the filter body (or the Frontier Pro UQC) and need to be trimmed down with a razor knife. The double female lets you fill an attached clean water bladder and also backflush the filter with a bladder.  

5. Camelbak Port Plug. You need to protect the fresh water end of your system from contamination and the Camelbak plug is the best choice. A cheaper option is a soft plastic thread protector from the hardware store that fits just over the end of the fitting.

I found the Camelbak Port Plug release button to be difficult to operate with the Frontier Pro UQC. I removed the plastic button/spring piece on the plug by pinching the “spring” portion together and lifting it out. I then trimmed down the guard lip around the button so I could get more fingertip on the button.

I also trimmed about 1/2 the thickness of the spring (“dishing” it out only on the sides away from the closed end of the cap) to reduce the pressure needed to press the button. I attached a loop of cord to reduce the likelihood of losing this piece.

I noticed the O ring of the Frontier Pro UQC was getting roughed up from the edges of the spring so I very slightly smoothed inside both ends of the spring. Keeping the O ring coated with food grade silicone grease will help. I recommend carrying a couple spare greased O rings.

While working out the fit and release problems with the UQC into the Camelbak Port Plug I found that the diameter of the UQC is slightly larger than a Camelbak Hydrolink.  The UQC was difficult to remove from the Camelbak Port Plug and the Hydrolock on the Camelbak bladder tubing. The O ring was occasionally being knocked off. 

Because of this I recommend another home built adapter - using a Platypus cap and a Camelbak Hydrolink adapter in place of the UQC.

Drill a tight-fitting hole in the top of a bottle or bladder cap (a Platypus cap is stronger than a SmartWater cap for this use – or even better use a Sawyer blue female adapter) and cut down the hose barb end of the Camelbak adapter.  Sand the contact areas and use plastic epoxy to secure the adapter to the cap. Trim down the sides of the cap to seal on the Sawyer filter. This adapter/cap will work better in the Camelbak Plug and replaces the Frontier Pro UQC and double female adapter, attaching directly to the filter body. The hose barb inside the clean water end of the filter may have to be trimmed down for clearance from this adapter/cap. An option is to use a Sawyer blue female adapter with 1/4” tubing connected to the Camelbak Hydrolink adapter.  This may not be as functional as the tubing can kink during use.

7. Additional ideas.
From your hardware store you can pick up a Watts PL-215 Nylon barb-to-MIP adapter 1/4” x 1/8”. Installed in a Nalgene wide mouth cap this will adapt a Nalgene Cantene or MSR Dromedary to 1/4” tubing and fit on either the dirty water or clean water hose barb of your system.

To drink directly from the Sawyer filter or a bladder you could use the cap from a 23.7 oz SmartWater bottle which has a better drink-thru cap (with attached cover) than the Sawyer cap. Trim down the cap so it will seal properly when attached to the clean water end of the filter.  Or Platypus has a bite valve cap (which will also need the sides trimmed down for a seal).

Putting it all together:
Starting at the dirty water end – place the wire mesh pre-filter into the cavity of the Frontier Pro pre-filter adapter, followed by a felt pre-filter disk. (You will notice that this adapter also has a tubing barb if you wish to use it with a gravity filter or in-line setup.) Then attach the Sawyer gray male adapter. This seals the dirty water end of the filter. If your filter didn’t come packaged with this adapter then you will need the hardware store thread protector to seal the Sawyer adapter hose barb. Attaching a loop of cord on the Sawyer adapter might be a good idea to avoid losing this piece.

On the clean water end - to fill a Camelbak bladder attach the Camelbak Hydrolink adapter/cap (or the UQC with the double female adapter if you prefer).  To fill clean water bladders or bottles attach the double female adapter.

The Camelbak Port Plug seals the clean water end and completes the Super System. 

Fill a soft sided bottle or bladder with dirty water and attach to the dirty water end of the filter.  Begin to gently squeeze the container and check for a tight thread seal.  Don’t twist or wring the bladder.  Roll it up as water is expelled. Treat the bladders with care to extend their life.

Don’t contaminate the clean water fittings with hands wet with dirty water.  The Camelbak adapter/cap prevents this. Dry your hands and use a little Purell that you carry in your filter kit.

Remove the pre-filter adapter and dirty water bladder before backflushing. Sawyer advertises that the Squeeze filter does not have to be backflushed as often as other filters, but with the double female cap or Camelbak adapter/cap it’s easy enough to backflush after every use.

The Sawyer Squeeze filter can be backflushed while attached to a clean water bladder by applying rapid pressure to the bladder. Watch the videos at Sawyer’s web site and experiment with the supplied syringe to understand backflushing. You are trying to dislodge particles – slow water flow will not work.

To store the filter after use - flush the filter with a diluted bleach and water solution and let stand for one hour. If you suspect a biofilm buildup is slowing the flow rate try soaking longer with this solution. If you suspect the flow is slowed by mineral buildup try flushing/soaking with a diluted vinegar solution. Drain the filter by shaking water out of both ends. If you must drain the filter faster you might try blowing on the clean water end (mouth only - not with a cold or flu). With even a slight amount of water in the micro tubes make sure the filter doesn’t freeze. Don’t seal the filter with the caps in storage before it has completely dried out.

Understand the limits of your filter as with any other vital piece of equipment. With up to 4 pounds of water in a wet and slippery bladder attached to the filter be careful to not drop it. I would recommend using the filter while kneeling. The Sawyer Squeeze filter is quick and easy to use. Adding a few parts makes it even more flexible and effective.

Addendum: In case you are wondering: I checked Sawyer's customer service desk, and they told me that their filters are manufactured in Safety Harbor, Florida. (Not overseas!)


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