Water Sanitation, Filtering, Bottles and Hydration Systems

Nalgene 1 liter water bottle

Nalgene makes several types of water bottles. There is one made of polyethylene and one made of polycarbonate. The polyethylene one is a has a milky, clear color, and is somewhat squeezable. The lexan one is much clearer, and is available in several tints, including clear. The lexan one is pretty rigid compared to the polyethylene one. The caps are available with and without the 'Loop-Top', which prevents the cap from getting lost.

These bottles are not very light, but they are extremely robust. They also have a nice wide mouth, which is mission critical if you need to use the bottle to melt snow. Of if you fill them with sugary drinks, you can easily stuff a towel in them to clean them. If you don't need the robustness or the large mount, you can use 2 liter soda bottles, or 1 liter poweraid or other sport drink bottles. They are pretty robust, weigh much less, and cost much less than Nalgene bottles.

I have had two polyethylene bottles fail in the same manner. They develop a series of cracks around the neck area. This really sucks, as the cracks usually aren't obvious until they leak. Therefore, I recommend only the lexan bottles. I tried to return the leaking bottle to REI, but I was told they simply wear out, and only the lexan ones have any kind of guarantee.

Hydrapak 3 liter drinking bladder

This is a 3 liter drinking bladder with a tube so you can drink while the bladder is in a pack. I have had 2 of them fail, and each time the failed bladder was replaced under the better than lifetime guarantee. When they work well, they are really great. The top of the bladder opens up so you can access the inside of the bladder, or even turn it inside out, which makes it easy to clean.

Platypus 2 liter flexible water bottle

This is a non rigid water bottles. I have had two of them fail, one with a slow leak, and one that ripped. Cascade Designs makes them, and they have a lifetime guarantee, which I used when my bottles failed. The warranty process is quick and easy.

Clean Water Overview

When I was a youth, I would go hiking, and dip my hand into a stream, and drink the water. That works great as long as the water is free of bacteria and viruses. Today, the only water I trust is directly from a spring. You can use chemicals to kill bacteria and viruses. Iodide is generally considered the best chemical. It kills viruses instantly. However, giardia which is really a protozoa takes much more contact with iodine to kill. According to the American Journal of Public Health, Mar 1986 Ongerth et. al. Backcountry Water Treatment to Prevent Giardia if the water is at 10 degrees C, it takes 8 hours to kill 99.9% of the giardia. Heating water to 70 C for 10 minutes will kill all the giardia, as will a good water filter.

If you have to rely on iodine, heat the water up as much as possible, and wait as long as possible before drinking the water. I remember adding iodine to fresh, cold water, and drinking it a minute later. In retrospect, it was quite foolish. Both iodine and filtration work best on clear water. You can use a shirt to filter water of some dirt. Another simple technique is to fill up a bucket, and let it sit for a few minutes. Some dirt will go to the bottom, leaving the water on top cleaner. I recommend discarding the bottom third of the water in general.

First Need Water Filter

My first water filter. I bought it around 1984-6. It uses activated carbon to do the filtering. The pump isn't easy to work and requires lots of effort to hold. It seems to take forever to pump as well. It has an inline prefilter (which predates the prefilter/float combination). It also predated the gravity filtering bag. You stuck the inlet hose in a stream, tried to pump and keep the outlet hose in or directed into a bottle. It seemed to take 3 or 4 hands to use. But it did work. I seem to recall the instructions for backflushing the filter being hard to understand. I also seem to recall reading that the filter was supposed to be thrown out after 2 years, but my instructions are long gone. I have heard that the backflushing procedure has a insignificant effect and exists to make people feel good.

Katadyn Pocket Water Filter

I had always wanted a Katadyn water filter, but they were very expensive. I ended up getting some used, for $50, $100, and $75 if I recall correctly. The Katadyn filters are made in Switzerland, and are built like user-serviceable Swiss watches. This filter has been around for a very long time, and is made of metal and plastic. It is designed to be serviced in third world countries. It uses ceramic impregnated with silver to do the filtering. The silver is supposed to kill viruses, but they can't advertise that in America for some reason. The ceramic filter is easy to clean. Most of the time, it is sufficient to simply wipe it off with a cotton shirt to clean the outside. For really stubborn dirt, they supply a nylon brush to brush the filter. It is rated to last up to 13,000 gallons. You can buy individual parts for the filter, including replacement filters. I used two filters to supply a group of 12 people water for 5 days in the Grand Canyon without incidence. I loaned one to a friend after a natural disaster and he used it to provide water to his family for a week without incident. It does take about 1.5 to 2 minutes to pump a liter of water. It is somewhat difficult to pump and you have to aim the outlet water nozzle into a water container while pumping. All the replacement parts such as O-rings are metric, which is a good thing.

MSR Water Filter

I bought a MSR WaterWorks filter. The main filter for it is activated carbon. I ended up getting the optional ceramic outside/carbon inside filter for it, as it was much more durable. This is now standard and known as the Marathon EX cartridge. The filter is very complex and mostly made out of plastic. It filters water very quickly. I have had it clog up in the field. There are some procedures needed to clean the filters that require clean water and denture cleaning tablets. It is more complex than the Katadyn and harder to maintain. When it is working, it is much faster and easier to use. As it is somewhat complex, there are many things to go wrong. I wouldn't take it out in the field without its instructions. It does have a very nice feature of screwing into a standard nalgene water bottle which makes filtering water much simpler than a Katadyn.

SweetWater Guardian Water Filter

The SweetWater Guardian is a nice compromise. It is fairly cheap, has a nice pump handle, is field cleanable and works quite well. Their inlet filter is much better than the MSR and I replaced my MSR inlet filter with the SweetWater version. The inlet filter feeds from the top, so it is less likely to pick up bottom debris. It is not as field cleanable as the MSR though. MSR bought SweetWater.

Gravity based Ceramic Water Filter

I bought a gravity based ceramic water filter. It it a big stainless steel pot with a top. On the bottom, there are three ceramic filters. By filling up the pot, water pressure pushes water slowly through the three ceramic filters, producing clean water. It filters several gallons a day, depending on how full you keep the pot. I bought it in case of urban disaster.

There is a much cheaper ceramic water filter now available. It is the Just Water Ceramic Drip-Filter It filters 1 gallon an hour with gravity feed, and up to 300 gallons per hour with pressure. You can buy it here. Everything except the bucket is $22.50. It is designed for third world use, though it would also work great in case of urban disaster.

If you have comments or suggestions, Email me at turbo-www@weasel.com

Created with gnu emacs and template-toolkit, not some sissy HTML editor.

No Java or javascript needed to view my web pages. They both have significant security issues.

Home