Reviews > Water Treatment > Filters > ULA Equipment H2O Amigo Water Filter > Clifford Haynes > Long Term Report

Ultralight Adventure Equipment
H2O Amigo Gravity Filter
Long Term Report
2/6/2005

Personal Stats:

Backpacking Background:
I am from and live in Maine. I have been hiking, backpacking, and canoe camping for over 45 years. I average 2 to 3 days a week in the woods year round.

I can't really say that I have a backpacking style. I take what I need or want, depending upon what I plan to do on the outing. Even before my knees became a problem, I could never see being in a big rush. It is my opinion that camping is part of backpacking, and should be enjoyed at least as much as the hiking. In areas where there is a lot of hiker traffic, I tend to pack heavier in order to minimize impact. I just like being out in the woods, and exploring.

Product Information:

Product Description:

The ULA H2O Amigo is a backpacking gravity water filtration system. The components of the H20 Amigo are; a water bag (unfiltered water reservoir) with sediment trap, prefilter, stop valve, tubing, and a 2-micron  WaterWise in-line filter. With the H2O Amigo, there is no more pumping or chemicals in the backcountry. Just fill the H2O Amigo's water bag with water and sit back while gravity does the work.

Component Description:
Water Bag (unfiltered water reservoir): The water bag is a disc of what appears to be coated ripstop nylon 24 in (610 mm) in diameter. There are 16 metal (appears to be stainless steel) grommets equidistantly spaced around the circumference of the disc. A pucker string is laced though the grommets and two plastic tubing handles 180 degrees apart. When the water bag disc is lifted by the handles, the picker strings gather the disc into a sack.

Prefilter: The prefilter is a plastic perforated strainer with an overall length of approximately 3 1/2 in (89 mm). The bottom is a male tubing connector, which protrudes through the bottom (to the outside) of the water bag. The strainer end (the part inside the bag) is about 1 3/4 in (44 mm) tall. The bottom row of open holes in the strainer is about 5/8 in (16 mm) above the bottom of the bag creating a sediment trap.

Stop Valve: The stop valve is a plastic stopcock with tubing fittings molded into both the inlet and outlet. When the handle of the stopcock is perpendicular to the tubing, the valve is off. When the handle is parallel to the tubing, the valve is open.

Tubing: There are three pieces of tubing. The first is a short piece of what appears to be 1/4 in (6 mm) I.D. silicon surgical tubing about 2 1/8 in (54 mm) long between the bag and the stop valve. The second piece of tubing appears to be 1/4 in (6 mm) I.D. silicon surgical tubing about 40 in (1 m) long between the stop valve and the WaterWise in-line filter inlet. The third piece of tubing is clear (Tygon type) 1/4 in (6 mm) I.D. tubing about 2 1/2 in (64 mm) long, which is attached to the WaterWise in-line filter outlet and is inserted into the drinking water container.

WaterWise Inline Filter: The WaterWise inline filter is a 2-micron pore size, activated coconut carbon core filter cartridge. According to ULA, the media within the filter deters the growth of bacteria, prolonging filter life. The filter removes microscopic pathogens, toxic chemicals and dissolved solids while also improving taste and appearance of water. The inlet and outlet of the filter are clearly marked, and are 1/4 in (6 mm) male tubing nipples. The WaterWise inline filter can also be installed into the drinking tube of most hydration bladders such as Camelback, Platypus, and MSR Dromedary Bags.

Flushing Bulb: The flushing bulb is a rubber funnel shaped gadget that is used to back-flush the WaterWise inline filter. The small end of the flushing bulb slides over the filter's outlet nipple, and the large end of the flushing bulb slides over the water faucet aerator as far as possible. Next the cold water is turned on slowly using medium pressure. The water running slowly backwards through the filter cleans the filter. New filters need to be back-flushed for about a minute prior to use. Assuming these filters are constructed like most filters, I would assume that the inlet water first flows through the carbon element and then through the 2-micron filter. If this is so, the reason one should back-flush a new filter before use is to remove carbon fines (tiny loose particles of carbon). If these fines are not washed out the inlet, they will be filtered out by the 2-micron filter, shortening the life of the filter element. It has been my experience with this type of filter, that back-flushing after field use before storage and prior to use after extended dry storage will extend filter life.

Long Term Report:

Shortly after filing my ULA Amigo Gravity Filter field report, I decided not to replace the leaky stop valve as soon as I had planned to. It occurred to me that if one were using the Amigo in freezing temperatures, the stop valve should be drained and left open. It seemed reasonable that if the valve were left closed with water in it, freezing could break (crack) the stop valve's body or it could freeze in position. Since I have been known to forget such things on occasion, I decided to abuse the old valve rather than a new one.

In the past I quickly tired on filtering water when hiking, and by midsummer I often switched to chemical purification and was looking forward to winter and melting snow. Thanks to this test, last summer I enjoyed filtered water into the cold weather. Since the field report, I continued to use the H2O Amigo to filter all of my drinking water while hiking and backpacking until the end of December (most of the water sources where I hiked were partially or completely frozen over). Normally after freeze-up, I melt snow for drinking water, but this year I continued to use the H2O Amigo for at least some of my water.

While hiking in freezing temperatures, I carried the WaterWise Inline Filter my jacket pocket to keep it from freezing. I was able to successfully filter water from a brook in temperatures as low as -3 F (-19 C). I normally would not filter water at such low temperatures, but I wanted to see it I could. After filtering about 3 L (3 qt), I stopped because the filter discharge tube was beginning to freeze. I thawed the H2O Amigo with some warm water prior to shaking out the left over water and packing it. I intentionally allowed the stop valve to freeze (I left water in the closed valve) over a dozen times. The repeated freezing did not appear to damage the stop valve or make the valve body leak worse.

Since the beginning of this test I have filtered 68+ gallons (257+ L) with the ULA H2O Amigo. I routinely back-flush and dry the WaterWise Inline Filter after each trip. For this report I repeated my filter flow test (see Field Report) and was surprised to find that the flow rate through the filter had increased from 871 ml (0.92 qt) per minute (measured at the end of the Field Report period) to 926 ml (0.97 qt) per minute. Apparently the frequent (at home) back-flushing after each trip cleared some of the sediment I clogged the filter with during the Field Test.

Durability:
After six months of use, my ULA H2O Amigo still looks new, The stitching is still in excellent condition and I could find no fraying on the Water Bag or pucker / hanging string. The grommets still appear new and the fabric has not pulled out of the grommet crimp or frayed around the grommets. The hoses are in excellent condition with no cracks, drying or checking. The stop valve body still has the pinhole leak but it has not worsened, even after repeated freezing. The valve is still tight and shuts off. The markings on the WaterWise Fiter are showing signs of wear, but are still readable. The stuff sack is exhibiting signs of wear, minor scuffs and fraying, which are probably the result of ridding under the seat of the moped or Jeep. I'm very happy with the apparent durability of the H2O Amigo.

Final Thoughts:
I like the H2O Amigo. It has become my preferred method of water filtration / purification and I have no intention of ever pumping water through a filter again. Filling the Amigo's water bag in cold weather can cause cold fingers, but I'd rather deal with that than pump. I also really like the fact that the H2O Amigo is relatively maintenance free. The prefilter and sediment trap are much more effective than I thought they would be. The only time I seriously clogged the WaterWise Inline Filter, I was filtering water containing very fine suspended solids, the filter clogged in spite of the effective prefilter. My son was filtering water at the same time with his MSR MiniWorks and his filter clogged too. I was able to field back-flush the H2O Amigo, but we had to dismantle and scrub  the MiniWorks. I have found that when I am filtering water from sources with fine suspended matter, I can avoid filter clogs by covering the mouth of one of my water bottle with a coffee filter, fill the bottle from the water source and transfer the prefiltered water to the H2O Amigo's water bag. When I'm done filtering water, I chemically clean the possibly contaminated bottle.  

I plan to replace the leaky stop valve now that the test is over and will continue to use the H2O Amigo as my primary water filter.  

Field Information:

Testing was conducted while backpacking, kayaking, canoeing and moped camping in western and northern Maine, at elevations between 300 ft (92 m) and 4000 ft (1200 m). The temperature during field-testing was between -3 F (-19 C) and 90 F (32 C). Precipitation experienced during testing consisted of light to heavy rain, freezing rain and snow. 

I would like to thank ULA Equipment and BGT for the opportunity to participate in this test.

Reviews > Water Treatment > Filters > ULA Equipment H2O Amigo Water Filter > Clifford Haynes > Long Term Report