Bushwalking gear and paraphernalia. Electronic gadget topics (inc. GPS, PLB, chargers) belong in the 'Techno Babble' sub-forum.
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TIP: The online Bushwalk Inventory System can help bushwalkers with a variety of bushwalk planning tasks, including: Manage which items they take bushwalking so that they do not forget anything they might need, plan meals for their walks, and automatically compile food/fuel shopping lists (lists of consumables) required to make and cook the meals for each walk. It is particularly useful for planning for groups who share food or other items, but is also useful for individual walkers.
Been thinking about this Sawyer and similar micro-filtration systems but have a concern.
Given that any water carrying utensil, especially one with nooks and crannies, it's almost impossible to prevent the growth of micro-organisms. As such, I can't be confident of the cleanliness/sterility over time of such a unit on its supposed "clean" end. Given its filtration technology, similar to those used in dialysis, it'd be next to impossible to dry them out once used. As much as the membranes will maintain a barrier between infused "from-the-wild" and filtered water, once there's bacterial/fungal growth on the filtered side, the objective has been lost. In the medical/health/laboratory field, these micro-filtration systems are typically one off use for a good reason.
Maybe I am too critical and the filter does not have to be up to medical grade, our body has far greater ability to resolve such contaminant. But has any of you guys considered this aspect? Has any of the longer term users carefully re-examined their unit? Yet again, I have at times found "yucks" inside my cycling water bottles and I have not suffered, yet.
They don't need to be dried after use, just backwashed. Though it is recommended to pass a teaspoon of bleach through them if putting into storage after use.
But really what's the need to keep the inside of a filter clean? Anything that might grow in there will be filtered out anyway. There should be no growth on the filtered side as obviously everything on that side has already been filtered.
Strider wrote:They don't need to be dried after use, just backwashed. Though it is recommended to pass a teaspoon of bleach through them if putting into storage after use.
But really what's the need to keep the inside of a filter clean? Anything that might grow in there will be filtered out anyway. There should be no growth on the filtered side as obviously everything on that side has already been filtered.
Yes, teaspoon of bleach would be a good practice.
The concern on growth is on the "clean" filtered side. Once a bacterial/candida colony establishes, it'd be near impossible to remove totally. With the non-sterile environment, there's every possibility it can happen in that moist environment. Then there's growth on the "dirty" side, these growths often have the capability to damage the filtration membrane, thereby rendering them ineffective. Maybe they should be seen as a disposable item than a perceived "life-time" item.
Anyway, it's just a concern I had. Guess I've spent too much time in the lab amongst other places and became instinctive.
Strider wrote:Make sure you get the SP129 as the SP131 was discontinued for reasons I'm sure Google will reveal. Highwater Filters were the cheapest I found, once postage was included.
Strider wrote:Make sure you get the SP129 as the SP131 was discontinued for reasons I'm sure Google will reveal. Highwater Filters were the cheapest I found, once postage was included.
Well that's a relief.........when I saw discontinued I thought $#@! whats wrong with the 131. There's not much difference really, it would appear that they just wanted to offer a cheaper product by reducing the number of water bags to 1 instead of 3. Both filter units are exactly the same as far as performance goes, they just have some minor design changes, minor improvements. Personally I like having a spare bag on hand. It weighs very little and if I was to damage one the spare one is insurance. My own filter is an SP131 according to the box but having watched this video I see that I have the latest version of the actual filter unit...... woo hoo!
Regardless of which model it is essential to avoid "cross contamination" between the inlet and outlet so be mindfull in handling and storing the filter. Don't pack it away with the caps off. After use the filter holds some water and without the caps it will drain out potentially contaminating the outlet (drinking end).
The SP131 bags are very weak and lots of failures were reported. The bag was redesigned accordingly and is now much much tougher - even tougher than Evernew bags. The filters are exactly the same between the two model numbers.
I've found Schweppes bottle lids fit best to keep the outlet clean as the cover the entire end of the filter and snug up nicely against the body.
Has anyone used quick connects in the sawyer water bottle? I'd like to use the same filter for my bottle during the day and gravity system in camp. The quick connects should save wear and tear on the silicone tubing when switching. I plan on using the filter from the sawyer 3 way in both cases. I know it works well with the Platypus gravity works, but I'm not sure how it'd go in the bottle and if the quick connects would let unfiltered water through.
Last edited by davec on Sun 28 Sep, 2014 10:00 pm, edited 1 time in total.
I have the sawyer three-way myself I'm not too sure what you mean by "sneaking through the back door" though.
They do not leak and will easily reattach. If you make sure to have varying male and female on both ends of the sawyer filter you shouldn't accidentally connect the wrong ones.
I have not used the grayl, but its a charged ion type filter. These are susceptible to certain water chemistries, and contaminants (like tannins) that can keep the filter from removing bacteria, so I'd say its limited to water from otherwise pretty high quality sources.