Silver Iones & Chlorine

When our mechanical filter failed in Mongolia, we were forced to look around for another water treatment. We then realized how incredibly expensive the Micropur tablets are, which we were carrying as an emergency option so far. With them a liter of treated water costs actually more than botteled mineral water! So certainly not an option for a long-term tour and budget-conscious travelers in general.

Back then, we decided in favor of chlorine, which is available as a detergent in many supermarkets either as tablets or liquids (domestic bleach / Javel). Furthermore it is really cheap. When buying, make absolutely sure that it is pure chlorine and not mixed with detergents (read the leaflet or the composition on the package)!

Liquid form: The EPA www.epa.gov recommends 2 drops per liter with a 6 to 8.25% household bleach.

Tablets: According to Aqua Tabs www.aquatabs.com 2-5mg Chlorine per liter is required for the treatment of drinking water, depending on the degree of pollution. This is similar to the dosage of Micropur Forte tablets (4mg / liter). The problem is that tablets for cleaning naturally contain much more chlorine and one can disinfect with one tablet up to 20 or 50 liters of water. We have therefore prepared an appropiate chlorine solution in a 100ml glass bottle to carry on and to dosage with a spoon.

The taste of chlorine has completely evaporated in the pet bottles during a day under the sun and the water was good to drink. Despite its ease of use, good efficacy and low cost, we would only use chlorine as an emergency back-up as chlorine for drinking water treatment (though used and relied on worldwide) has adverse health effects in some long-term studies.

Note: It is also possible to flush from time to time a chlorine solution through mechanical water filters or drinking bottles to prevent the growth of mold and to keep them germ-free. Chlorine-treated water is ready to drink after half an hour.

Conclusion: Belongs in every baggage as an emergency option, as it is small, cheap and reliable. Available everywhere.

Boiling

For the evening tea or the breakfast porridge we usually boil the water on our petrol stove. If we are at high altitudes or fuel supply is scarce, we filter the water beforehand to save gas.

Conclusion: Not suitable for covering daily water consumption, but a good option if the stove is running anyway.

Steripen (UV Light)

Our Steripen time was short. Already after a week the diodes on the pen blinked happily in green and red and we could never be sure if the disinfection had worked or not. We immediately changed back to a mechanical filter. However, we also know of bikepackers who have treated their water for months with their Steripen without any problems. We just had bad luck. Neverthless, the fact is that treating by Steripen is not faster than with a modern mechanical filter (Steripen: 90 sec / liter), in addition, you carry another electronic device that needs to be charged.

Conclusion: If you want to rely on electronics in water treatment and if you can count most of the time on clean water sources, this is certainly a lightweight and compact option. Taking into account the energy / environmental problem of batteries, a USB rechargeable model is mandatory.

Katadyn Pocket (Ceramic filter)

For decades Katadyn's Pocket Filter was an essential part of our luggage. It filtered reliably brown water out of Sudanese rust barrels or muddy water in Sweden‘s swamps. If the filter is dirty, the ceramic filter cartridge can be scraped with a scratch sponge and it becomes like new. The pumping takes some time and effort, also the filter is quite heavy, but almost indestructible. The cartridge has a filtration capacity of up to 50'000 liters and suffice therefore also for the very long tour, without having to worry about a replacement.

Conclusion: A very reliable, almost indestructible filter that lasts forever and, calculated on the liter of water, is inexpensive. Because of the weight and the slow pumping technique we do not use this filter anymore.

Katadyn BeFree (Squezze Filter)

Small, super light and handy. The flow rate of the first ten liters through the BeFree was fantastic. But then it worsened quickly. Barely six hundred liters of mostly clear water we could filter with it, then it was definitely clogged. Price and performance ratio are bad and in cooler weather you get blue fingers when pressing the thin TPU flask. The filter can only be screwed on this specific and much too small flask. If it breaks (has happened to us), it is over with filtering...

Conclusion: For individuals and day trips in warm weather a great option, but not suitable for long-term use.

Swayer / Careplus (Squeeze Filter)

Swayer / Careplus (Squeeze Filter):
The indication of the flow rate on the filter (375'000 liters :-) is a joke! The filter is good for about a thousand liters, then also backwashing with the syringe does not help anymore. However, it is super small, lightweight and inexpensive compared to similar products. So it is easy to carry a replacement. If the original squeeze bag breaks, the Swayer fits on every pet bottle. Considering the flow rate an the effort of filtering it is approximately the same as a ceramic pump filter. The filter is neither break- nor frost-proof.

Conclusion: Cheap, super-small filter for medium-length tours (or with appropriate planning of a replacement for the long tour). Short life, considerable time / effort per liter.

Katadyn Gravity Basecamp (Gravity Filter)

The Katadyn Gravity Camp Filter was a revelation to us: no more strenuous filtering, instead the water filters by gravity almost for itself. In our view, the concept of the new gravity filters means death for all pump or press filters. The flow rate decreases over time, it lasts about half a year in continuous use (for two people). Since the filter is integrated in the water bag it remains wet. So it must be regularly dried and rinsed with a chlorine solution to prevent the growth of mold (especially in humid climates).

Conclusion: A filter with high flow rate, simple, light and easy packable. Requires care to prevent odors and mold. Thanks to the membrane filter, it survives an occasional punch. Relatively short lifetime.

MSR Autoflow (Gravity Filter)

After our experience with Katadyn's Gravity Camp, it was clear that no other model would be traveling with us. So far, the MSR Autoflow filters reliably and (differently to the Katadyn) can be backwashed. The recommendation of a backwash after eight liters of filtered water is a bit out of reality in everyday use. The flow has already decreased noticeably and we do not like the handling of the filter hanging outside the water bag as much as the Katadyn. The filter is not break- and frost-proof.

Conclusion: A good filter, lightweight, relatively compact, but not so practical in handling for us. Dropping can destroy the hollow fiber filter without knowing it for sure.

Attention: All mechanical filters are sensitive to extreme cold. Water in the filter cartridges may freeze and the ice may burst the filter. Therefore water filters need to be stored in the sleeping bag at minus temperatures!

Socks & Co.

Who has not heard that heavily polluted water can be prefiltered with a sock? Who gives this tip has never tried it. The textile structure is far too coarse, as that there would be prefiltered any water. Neither does work a coffee filter, because firstly it is not always available, and secondly it must be replaced after a pint of dribbling... If water is so dirty that we fear ruining our water filter, we leave it overnight in the water bag of MSR Autoflow or Katadyn Gravity Camp to let sink the filth. The filters are designed that the outflow is above the bottom of the bag, so that the water with the settled particles does not run through the filter. If you have little time, only chlorine helps: Chlorine is the only water sterilization (except boiling), which also works in cloudy water (dose higher and let it work longer).

In countries with high levels of pollution (China, India, ...) we treat ourselves to mineral water because none of the treatment methods listed above can detach chemicals out of water.