Friday, July 30, 2010

MSR Miniworks EX Water Filter

There are a number of good options on the market today when it comes to cleaning your drinking water in the woods. Here I want to give you a brief overview of the MSR Miniwirks EX filter, and explain why I chose to use it over the other options on the market.

Weight: The MSR Miniworks EX comes in at 14.6 oz.
Filtering Element: The MSR Miniworks EX uses a field cleanable ceramic filter element with a carbon core. The pore size of the filter element is 0.2 microns.
Filtering Speed: The MSR Miniworks EX filters one liter per minute.
Cost: The MSR Miniworks EX retails for $90.00.

The Miniworks EX is a hand operated filter, meaning you will have to pump it. The specifications state that it will pump one liter of water per minute, although I can tell you that the pumping rate is effected to a large degree by the quality of the water.

The filter uses a ceramic filter with a carbon core. The pore size of the filter is 0.2 microns. That makes it effective against protozoans such as giardia and cryptosporidium as well as bacteria. The filter will remove sediment and particles from the water, and the carbon core removes some of the chemicals and taste. Viruses however will not be removed and if they are a concern in your particular area, you should carry an additional chemical treatments like chlorine.

The Miniworks EX is not light. It weighs 14.6 oz. The filter element however is good for up to 2000 liters, and more importantly, can be cleaned in the field. The cleaning process is quite simple. You just unscrew the top of the filter, pull out the ceramic element and depending on how dirty it is, you can either just wipe it down, or use the provided scrubbing pad to scrub off a layer from the top of the filter. Put it back in and you are good to go. The whole process takes about two to five minutes.

So, why do I use this filter. Well, it is mostly because of the area in which I mainly backpack. The terrain in my area is very rocky, and any rain runs off quickly. Most times of the year, water is hard to find. You will not run across many clear flowing streams. As a result, most times I will be pumping water from a puddle or a swamp. The quality of the water tends to be low.

MSR Miniworks EX vs. Chemical Treatment

Because of the low quality of the water, chemical purifiers are out for me. First of all, it is only recently that chemical purifiers have developed to the level where they can kill cryptosporidium. The old standbys chlorine and iodine were not able to do that. Newer solutions like chlorine dioxide, and MIOX can get the job done, but take up to four hours. That is just too slow for me.

The second, and more important reason is that it is crucial for me to remove all the garbage out of the water. I do not want mud or insects or amphibian eggs in my water. Chemical purifies do nothing to address that problem, and filtering through something like a coffee filter does little to remove anything other than the very large particles. Like I’ve said before, purified swamp water still tastes like swamp water.

That leaves out purifiers. Now, why this filter over other filters? The models which I consider competitors and would consider buying are the Katadyn Hiker Pro, the Katadyn Vario, the Pre-Mac Travel Well Trekker, and the MSR HyperFlow filter. I will also consider the Katadyn Pocket, although I do not consider it to be in the same league of products.

MSR Miniworks EX vs. Katadyn Hiker Pro

Weight: The Katadyn Hiker Pro weighs 11.0 oz.
Filtering Element: The Katadyn Hiker Pro uses a glassfiber filter with a carbon core. Pore size of the filter element is 0.3 microns.
Filtering Speed: The Katadyn Hiker Pro filters one liter per minute. Cost: The Katadyn Hiker Pro retails for $80.00.

The reason why I use the MSR Miniworks EX over the Katadyn Hiker Pro is because of the filtering element. I have found that in water which contains fine sediment, filters get clogged in a very short period of time, maybe even after filtering just a litter or two of water. With the glassfiber filter of the Hiker Pro, you would have to replace the filter. The Miniworks EX on the other hand is field cleanable. Even in the worse conditions, the filter can be removed, cleaned, and put back without any tools. Considering that I rarely use clear water sources, the glassfiber filter was a non-starter.

MSR Miniworks EX vs. Katadyn Vario

Weight: The Katadyn Vario weighs 15.0 oz.
Filtering Element: The Katadyn Vario uses a glassfiber filter with a carbon core. Pore size of the filter element is 0.3 microns. The Katadyn Vario also has a ceramic pre-filter which can be put in place if the water source contains a lot of sediment.
Filtering Speed: The Katadyn Vario filters two liters per minute with just the glassfiber element.
Cost: The Katadyn Vario retails for $90.00.

The Vario is a theoretical improvement over the Hiker Pro, but it is just unclear what the advantages over the MSR Miniworks EX are. Its main filter is still a glassfiber one, so I have the same issue as I did with the Hiker Pro. The addition of the ceramic pre-filter is a good one, but then again, the Miniworks EX is an all ceramic filter. The Vario seems to add unnecessary complexity for the gained benefit of faster filtering when the ceramic element is removed. To me the benefit is not worth the sacrifice in durability.

MSR Miniworks EX vs. Pre-Mac Travel Well Trekker

Weight: The Pre-Mac Travel Well Trekker weighs 6.4 oz.
Filtering Element: The Pre-Mac Travel Well Trekker uses a fiber filter with an iodine-resin complex. I was unable to find the pore size of the filtering element, but because the water is passed through the iodine, it functions as a filter-purifier combination, which should serve to kill all bacteria and viruses left in the water after the filtering.
Filtering Speed: The Pre-Mac Travel Well Trekker filters 0.4 liters per minute.
Cost: The Pre-Mac Travel Well Trekker retails for $110.00.

The Pre-Mac is a British made filter which seems to hold a great advantage. That is because it is both a filter and a purifier. It has a fiber filter as well as an iodine core which purifies the water as well as filtering it. This makes it effective against sediment, parasites, bacteria and viruses. Remember that the Miniworks EX does not do anything against viruses. Combined with the low weight of the filter, it should be a no brainer.

The truth is that I specifically did not like the Pre-Mac for this very reason. I do not want a filter-purifier combination. I want my filter to be as simple as possible. In North America, viruses are not much of an issue. Unless you are in some area where you think there is human contamination in the water, disinfecting for viruses is massive overkill. That being said, I carry with me a small bottle of SweetWater chlorine solution. If I think the water is especially suspect, I will add five drops. That will kill any viruses in the water. I like having the option of not putting chemicals in my water unless I feel it is necessary.

The second reason why I prefer the Miniworks EX is the ceramic filter. Again, the fiber filter is not field maintainable. On top of that the Pre-Mac Travel Well Trekker can only filter up to 250 litters before the filter has to be replaced. That is almost ten times lower than any of the above filters. This will significantly increase the running cost, as each replacement filter is around $40.00. Also, while I am not a person who does nuts over the speed of the filter, the Pre-Mac Travel Well Trekker is two and a half times slower than even the slowest of the above filter.

MSR Miniworks EX vs. MSR HyperFlow

Weight: The MSR HyperFlow weighs 7.8 oz.
Filtering Element: The MSR HyperFlow uses a hollow fiber filter element. Pore size of the filter element is 0.2 microns.
Filtering Speed: The MSR HyperFlow filters three liters per minute.
Cost: The MSR HyperFlow retails for $100.00.

While the HyperFlow can pump water three times faster than the Muniworks EX and is much lighter, I did not chose it for the same reason as with most of the other filters-the filter element. Considering the type of water I filter, a fiber filter is not the right choice for me.

The HyperFlow can be field cleaned by reversing the valves and using some clean water to back pump it. I have found this process to be unreliable and time consuming. I have found myself in situations where I have simply not been able to back pump the filter because it has been so clogged. This is not something I want to deal with even if I have a source of clean water with which to back pump. The fact that a filter is light in your backpack does not mean much when it can not filter your water.

MSR Miniworks EX vs. Katadyn Pocket

Weight: The Katadyn Pocket weighs 20.4 oz.
Filtering Element: The Katadyn Pocket uses a ceramic filter element. Pore size of the filter element is 0.2 microns.
Filtering Speed: The Katadyn Pocket filters one liter per minute.
Cost: The Katadyn Pocket retails for $290.00.

The name "Pocket" is perhaps a bit of a misnomer here. The filter weighs significantly more than any of the above filters. It has a filter pore size that is the same as the Miniworks EX, clearly also ceramic. Filtering speed is the same. The big advantage of the Katadyn Pocket is its durability. It has a metal body, and the filter element can last for up to 50,000 liters as compared to 2,000 for the Miniworks EX. Keep in mind however that a replacement filter for the Katadyn Pocket is about $180.00. The main reason why I do not consider this filter to be in the same league as those listed above is the cost. It is about three and a half times the cost of a MSR Miniworks EX. It provides the same benefits as the Miniworks EX (same speed, same pore size, field cleanable), but is built in a more robust manner. At three and a half times the cost however, it can afford to do all of those things.

None of the above filters should be considered "bad". The reason why I mentioned them is because they are respected and widely used by many people around the world. As you can see, most of them have very similar specifications. The reasons for my choice are personal ones. I like durable and robust equipment, and the conditions in my area lead me to prefer a ceramic filter such as the MSR Miniworks EX. Using it is certainly not a walk in the park. If I am using a water source with a high amount of fine sedimentation, I might have to take out the filter and clean it after every few litters pumped, but I can keep it working under even those conditions while other filter would probably fail. After over three years of use, it has not failed me. Pick the filter that is right for your conditions.