Monday, January 17, 2011

Filtering Water

Our rain barrels have long been used for most of our water needs. However, the main thing that was missing from our house was a water filter. Until we could filter the water adequately, we weren't going to risk drinking or cooking with it. It never seemed to kill the dog, but then she likes to eat cat poop and I have a feeling that might just kill me.

Over the summer we stumbled upon an estate sale and picked up our MSR MiniWorks Expedition filter for about 7 dollars. Estate sales are the BEST for gear. We have since filtered all our water here at the house for both drinking and cooking. It works out to be about 4 gallons a day which is filtered with the morning chores. I really like it and I'm getting bicepts of steel!

With recent reports about the carcinogens in city tap water, I'm equally happy we have completely pulled off the central grid for our ingestion. Our city is not on this list, but a really close one is! Even before this report came out, it always bothered me that our family is pulling chemicals out of our food, but not our water. We don't need to be ingesting chlorine, or fluoride, or the pesticides and hormones which are known to exist in city water supplies.

We carry the same filter (MSR MiniWorks EX) when we backpack as we use at home. I refuse to go ultra light here. There is absolutely no reason to ingest chemicals with your water. There is no such thing as a benign chemical. If people insist on chemical free food, they should insist on chemical free water.

The filter with the toothbrush to clean it weighs 1 pound.


There are many different types of water filters out there, but the main thing to realize is a water filter has to clog. If it isn't clogging, it isn't filtering the junk out of your water. For this reason, the physical filter is the most important thing to remember. You are going to have to clean it, replace it, and trouble shoot issues with it. If you don't, the filter isn't working.

Micron Filter Level
All the talk when it comes to water filters is about mircons. A micron is the measurement of all the small little particulates which float around in the water but are unseen to the naked eye. The water filter catches these particles by having holes which are so small the impurities cannot flow through. Those holes are measured in microns as well. You want your water filter to have small enough holes it catches the bad stuff and lets the good stuff through. Chryptosporidium and Guardia are both 1 micron in size so smaller is necessary. Viruses can be filtered out using a filter of .01 microns or smaller. Any water filter worth its stuff is less than .1 microns.

Ceramic Filters
I will openly admit being a fan of these filters. They are the most durable, the easiest to clean, and the longest lasting. They are a bit overkill for many weekend warriors, but for our lifestyle I wouldn't purchase anything else. They cost more initially, but will save you lots in the long run. They are what the Peace Corp and Mercy Corps use in disaster zones because of their ease and bomb proof simple workings.

Ceramic filters are made of the material Diatomaceous Earth. This stuff does a million and one things and one of them is filtering things down to a .009 microns. The smooth outer surface is porous and much like sand stone in make up. They are cleaned by using a toothbrush to scrub off the most outer layer. The problem many have with ceramic filters is their weight. Because the filter is brittle in nature, the housing is often made of metal or high grade plastic to protect the inner workings. These filters are slower, due to their density, but last much longer.


Paper Durable Filters
Durable paper filters have accordion folds and honeycomb pleating designed to create the filter. Each layer of paper filters down to a lower micron level and the end result is filtered water. The filters are then impregnated with a chemical like carbon or charcoal to help remove and disinfect. These filters can be carefully cleaned a few times, but ultimately must be thrown away and replaced. They will get holes in them, and just plain wear out. This means you either need to carry a back up or have complete knowledge you can find your exact filter at an outfitter on the trail. I'm not a big fan of disposable items, but I can understand the desire to go with a lighter weight option. These aren't bad filters and Jules used one for his entire AT hike.
To clean you gently scrub down each of the pleats, renewing the filter for more use.


Paper Disposables
These filters bother me. They are layers of paper wrapped around a cylinder or coming out in a star pattern around a central shaft. These are extremely light weight, cheap filters. The catch is, they cannot be cleaned. The filter will last a long time, but then just goes to the landfill. Depending on how long you are going to be out, it can mean you don't need to carry a direct replacement. However, if you want to own the same filter for a while, stock up. Once the exact filter for your model is discontinued, you are out of luck. These just bug me from the environmental standpoint. You are out enjoying nature at the expense of nature itself. Something about that rubs me wrong.

These are the types of filters which are often in Britta and other countertop filtering systems. They are also the ones which are inside cheaper outdoor filters.

Disposable Disk Filters
These are weekend warrior filters. They are one time use, rather flimsy, and don't need to be cleaned. Water is forced through a single thick pouch of carbon which collects any impurities. The disk filter is then thrown away and the next time you need water you grab another disk. Again, this is a disposable option and not my favorite. However, if you don't get out much, this is the way to go. Multiple filters use the exact same style disks and there is no worry that your model is going to go out of style. It is important to remember practicing leave no trace means you are then carrying about these water laden, round disks which can get smelly after a bit.

Chemical Treatment
As stated above, I am against chemical treatments of water. Yes, they are light. Yes, they are often fairly cheap. And yes, as a child I ingested them because my family did. However, it is important to remember there is a trade off for every easy, cheap decision that you make. I'm not trading anything when it comes to my water supply.

All bacteria are not bad. Your gut is filled with bacteria which are necessary to our survival, because they digest and intake nutrients. When you ingest anything which is designed to suppress or kill bacteria on a broad scale you are hampering your bodies ability to digest and remove nutrients from your food. Unless you are also carrying a pro-biotic to balance out the bacterial water treatment, you are physically harming your system and hindering your ability to perform optimally. As an adult, I can make this choice with full knowledge. My son is 6. He cannot make this choice with his current depth of knowledge. I feel it is imposing far too much for me to give him chemicals without his full consent. I would never knowingly ask my child to drink bleach, iodine, or even chlorine dioxide, why would I put it in his water?

If I filter rainwater for us to drink at home, I will filter the stream water we drink outdoors.

3 thoughts:

Erin McKittrick - Ground Truth Trekking said...

Have you tried the UV type sterilizers (like Steripen)? Small and light and lasts, neither chemical nor a filter. We used to not treat much water, but are more cautious with a 2 year old along, and used the steripen all last summer.

Anonymous said...

Thanks for the run down on filtering. I will soon be looking for something to filter river water for drinking.

You write: There is no such thing as a benign chemical.
and then

The filters are then impregnated with a chemical like carbon or charcoal to help remove and disinfect.

Granola Girl said...

Erin - Thanks for the idea. Neither Jules or I know much about UV other than its uses in some foreign countries as a source of water purification for native populations to avoid privatizing water. We are rather nerdy about our documentaries :) We are going to look into it. Isn't it amazing how much you being to wonder about some of your seemingly normal actions when you have a kid?

Anonymous - Many filters do contain a level of chemical, however, I do not use those. The only type of filter used in our household is a ceramic for this very reason. I feel that chemicals in water supplies are a problem. It is the same way I feel about disposables. This is why our family doesn't. It doesn't mean that they aren't a viable option for others. On the spectrum of damaging, charcoal is much less harmful than chlorine.

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