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

Ultralight Adventure Equipment
H2O Amigo Gravity Filter
Field Report
10/10/2004

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 is slid over the filters outlet nipple, and the large end of the flushing bulb is slid onto a water faucet 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.

Field Report:

Home test:
Shortly after posting the Initial Report, I decided to do  a bit of home testing of the H2O Amigo. I filled the water bag with tap water to check its volume. The water bag does in fact hold 1.25 gallons (4.73 L), but it can be a bit challenging to fill if it isn't dipped into the water source. I found it was rather difficult to hold all of the folds in the top of the puckered water bag open while pouring water into it. After the water bag was full, I noticed a leak in the vicinity of the stop valve. Careful inspection revealed a small crack in the body of the stop valve. Unfortunately I didn't water test the Amigo upon receipt or prior to the Initial report, so I can not honestly say for sure that this is a manufacturing defect. 

In order to test the filtration rate, I measured the volume of water delivered to a 1000 ml (1.05 qt) graduated cylinder in 1 minute as timed with a stop watch. I determined my filtration rate to be 1563 ml (1.61 qt) per minute. In my opinion the difference between the advertised filtration rate of 1.7 L (1.79 qt) per minute and my measured rate of 1.563 L (1.61 qt) per minute is due to the leak in the body of the stop valve.

Field Use:
After my home filtration rate test, I emailed ULA and requested more information regarding flushing the H2O Amigo in the field, and the availability of replacement hose and stop valves. I promptly received this reply from Brian Frankle: "To flush in the field I prefer to use filtered water. You really need some sort of hydration bag/hose set-up to do it, like a Camelback or Platypus drinking system. Fill the Platy bag with filtered water and hook up the hose (after removing the bite valve) to the OUT side of the filter cartridge. Once the hose is secure, apply pressure to the Platy to force the clean water back through the filter assembly." Brian also advised me that the valve and hose were available and reasonably priced. I did not request warranty replacement of the stop valve because I didn't feel I could honestly say the leak was a manufacturer's defect. I decided I would wait until later in the test and order a new stop valve and spare WaterWise filter. I want to see if the valve body leak gets worse or completely fails (I can live with the leak, I just have to be careful not to cross contaminate). 

My first trip into the field with the H2O Amigo was a 3 day bushwhack. I expected water sources to be plentiful, so I only carried the 2 L (70 oz) Platypus and a 32 oz (946 ml) spring water bottle as water reservoirs. My first water stop was a small cold, clear spring, at the base of a small steep ridge. The runoff was insufficient to dip the H2O Amigo's water bag. Fortunately I was able to fill the bag about 3/4 full quickly, by opening one of the bag folds to catch the water as it ran out of the side hill. I found a tree limb that was the right height and hung the Amigo's water bag and attached the WaterWise inline filter. After positioning the filter's outlet tube in the mouth of my empty spring water bottle, I opened the stop valve and simultaneously tipped over my spring water bottle. I had to pick up and hold the bottle and filter while opening the stop valve. After the valve was open, I was able to set the bottle on the ground while it filled. Next I prepared to refill the Platypus. It became immediately obvious that I was going to have to sit there and hold the Platypus while it filled because it wouldn't stand up alone while filling. By the time the Platy was half full it dawned on me that if I could back-flush from the Platy, I could also fill it by attaching the Platy hose to the filter outlet. I dug the Platy hydration hose out of my pack, squeezed the air out of the Platy, attached the hydration hose between the Platy and H2O Amigo, and filled the Platy with filtered water while grabbed a short nap in the shade. As I was preparing to unhook and repack the H2O Amigo and Platypus, it occurred to me that I could back-flush the WaterWise filter with a small amount of the filtered water from the Platy, before I unhooked. While this probably isn't enough flush volume to amount to much, it certainly can't hurt. Since, I have routinely filtered into the Platy, filled my bottles from the Platy, refilled the Platy, and performed a mini back-flush of WaterWise filter.

Since the first outing, I have carried and used the Amigo on weekly outings the longest of which was a 5 day canoe trip on which I filtered drinking water for both my wife and myself. My wife and I have enjoyed numerous showers in the field with the H2O Amigo. We normally fill the water bag with warm water, scrub with a wet bandana and small bar of Ivory soap, and then enjoy the warm water rinse from the Amigo water bag. In my opinion, there is nothing that tops a full belly and a warm outdoor shower just before I crawl into my sleeping bag.

I have also come to enjoy having the Amigo's water bag as a source of water for those camp chores that don't really require filtered water. Often when I am alone, while breaking camp, I can just filter the water left in the Amigo water bag in order to refill my water bottles. I used to hate having to filter water in the morning before hiking.

The prefilter and silt settling chamber have worked quite will (better than I expected). I have only clogged the WaterWise filter twice. On both occasions I was filtering from water sources (a small pond and a small river) containing fine suspended organic matter. On both occasions I was able to clear the filter by back-flushing in the field with chemically treated water. I certainly don't consider these clogs to be a failure of the WaterWise filter as my son's pump filter also clogged from the same sources.

I have made it a habit to back-flush the H2O Amigo's WaterWise filter and thoroughly dry it before storing when I get home.

Final Thoughts:
The ULA H2O Amigo Gravity Filter has performed well for me thus far, I have filtered approximately 27+ gallons (102+ L) of water. The Amigo's water bag can be difficult to fill from small shallow water sources and I have had to use my cook pot to bail water into the water bag on several occasions. My inspection of the Amigo prior to writing this report revealed no evidence of wear or fraying. The hoses (tubing) are in good shape and have not stretched or hardened. The crack and leak in the body of the stop valve does not appear to have worsened. 

The filtration rate has decreased from 1563 ml (1.61 qt) per minute to 871 ml (0.92 qt) per minute.

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 40 F (4 C) and 90 F (32 C). Precipitation experienced during testing consisted of light to heavy rain.

Test Plan:

I plan to continue to use the H2O as my primary water filter. As the damaged stop valve has not catastrophically failed yet, I will soon be ordering a replacement valve and spare filter. As winter approaches my interest will be shifting to cold weather performance and difficulty in using the filter in freezing weather. I will continue to monitor durability, reliability and ease of use.

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 > Field Report