Since you've run water through the 2nd filter, you cannot let it freeze or it will be ruined. As the water inside freezes, it expands and creates gaps in the fibers, which could allow bacteria to pass through. They can be kept in freezing conditions as long as they have never been used.
After this test, I backflushed the Sawyer Mini three times with tap water, pushed 3x air through it to get most water out, and then put it in the food dehydrator together with the test samples. So in theory it should be completely dry again after 48 hours near human body temperature and constant air flow. But you´re mentioning an important point: If filter is wet don´t let it freeze. Manuel; DL2MAN
@@dl2man I'd be curious to know if that actually works. It was my understanding that the fibers are so close together that it's virtually impossible to get all the water out. If it works, I might give it a go so I can stop sleeping with mine every winter lol.
Last time I took a Sawyer filter on a hike, it didn't work. Not a single drop of water would pass through it. I'd used it on another hike, but the water I filtered wasn't particularly bad, as I recall. I'd only used the filter on that one occasion since backwashing it. So it seems that storing these filters in a slightly used condition can lead to clogging. Therefore, I am not a fan. If you have to backwash every time you use them to avoid clogging then they require too much maintenance for me.
Hi John, I would still recommend the Grayl for backpacking trips after what I´ve seen. This is why I bought a second one in combination with a millibank bag. 73 Manuel; DL2MAN
Hi, I have a original life straw and a off brand copy. Both sealed and never used. Problem with those types of filters is: They are intended to be used with your mouth to drink directly from a water source. I´m not a fan of this, as water sources might not be available constantly along the way, and I´d like to fill up my water containers, once I´m at a water source. There´s no way to do that with a life straw. You can just drink with it. Other downside of those straw type filters: They work with the same technology as the Sawyer Mini (hollow fibre membrane tube bundles) and should be tested before actual use. And to do that you´d need to use the "syringe trick" I did with the Ahlstrom filter. However: In real world, clean side could be contaminated anyway as the function of those filters is to put your mouth to it and the bacteria from your mouth can grow and contaminate the clean side.
Since you've run water through the 2nd filter, you cannot let it freeze or it will be ruined. As the water inside freezes, it expands and creates gaps in the fibers, which could allow bacteria to pass through. They can be kept in freezing conditions as long as they have never been used.
After this test, I backflushed the Sawyer Mini three times with tap water, pushed 3x air through it to get most water out, and then put it in the food dehydrator together with the test samples. So in theory it should be completely dry again after 48 hours near human body temperature and constant air flow. But you´re mentioning an important point: If filter is wet don´t let it freeze. Manuel; DL2MAN
@@dl2man I'd be curious to know if that actually works. It was my understanding that the fibers are so close together that it's virtually impossible to get all the water out. If it works, I might give it a go so I can stop sleeping with mine every winter lol.
Last time I took a Sawyer filter on a hike, it didn't work. Not a single drop of water would pass through it. I'd used it on another hike, but the water I filtered wasn't particularly bad, as I recall. I'd only used the filter on that one occasion since backwashing it. So it seems that storing these filters in a slightly used condition can lead to clogging. Therefore, I am not a fan. If you have to backwash every time you use them to avoid clogging then they require too much maintenance for me.
Your research has convinced me to look at other sorts of water purification than small filters. Thanks.
Hi John, I would still recommend the Grayl for backpacking trips after what I´ve seen. This is why I bought a second one in combination with a millibank bag. 73 Manuel; DL2MAN
Thanks, coincidentally I've been looking at the life pen. Water filtration pen. Have you tried these ones?
Thank you for all you do!
Hi, I have a original life straw and a off brand copy. Both sealed and never used. Problem with those types of filters is: They are intended to be used with your mouth to drink directly from a water source. I´m not a fan of this, as water sources might not be available constantly along the way, and I´d like to fill up my water containers, once I´m at a water source. There´s no way to do that with a life straw. You can just drink with it. Other downside of those straw type filters: They work with the same technology as the Sawyer Mini (hollow fibre membrane tube bundles) and should be tested before actual use. And to do that you´d need to use the "syringe trick" I did with the Ahlstrom filter. However: In real world, clean side could be contaminated anyway as the function of those filters is to put your mouth to it and the bacteria from your mouth can grow and contaminate the clean side.