Wednesday, April 26, 2017

Armed for bear: My favourite portable water filters configuration

For today's post, let's move away from serious talk such as national water supply and dive back into water filters.

When I am outside of good old SG where the water (tap or otherwise) cannot be relied upon to be safe (biologically at least), I trust my health on the water treatment that has never failed me (yet) - good old boiling. Boiling is great against microbes and parasites! For good measure, I prefer to get a rolling boil for 3min though some literature quote that 1min is enough.

But let's face it - boiling requires a good source of fuel (e.g. finding dry wood can be a pain after a heavy downpour in the middle of the jungle) and a big enough pot (typically metallic which can another pain to carry along in the bush). This is not to mention that you have wait... for the boiled water to cool down before drinking.

Therefore in cases for which the above conditions do not apply (e.g. no fuel, no pot, need to drink now), I rely on a handy package to treat my water.
  1. I have already introduced the Sawyer Mini filter before. What's not to like about it? It is small and versatile, removes most bacteria and parasites (99.99999% and 99.9999%, respectively) and super high capacity (100 000 gallons!).
  2. To squeeze even more performance out of my Mini, I hook it up to a Platypus Gravityworks Carbon element. Containing granular activated carbon (GAC), it is good to remove odours and taste due to organic compounds and chlorine.

    However, compared to the Mini, this little guy is only rated for 300L capacity, depending on the water quality so expect to replace it long before the Mini. There is also a slight increase in resistance when the 2 are connected together so be prepared to suck or squeeze harder to get drinkable water but it's nothing that cannot be overcome.

    Finally, the most important caveat... it is not designed to remove dangerous substances such as pesticides, solvents, heavy metals, radioisotopes... so if you have a reason to suspect such nasty stuff in your water, forget filtration and look for another water source.
  3. Not forgetting another nasty group of microbes - the viruses. I have posted before about the Steripen and how convenient it is. (Update by author on 13/5/18: This particular model of Steripen, Journey (no longer in production) is designed for only 50L of disinfection before requiring a change of batteries - 2x CR123. Wow! This is pathetic considering 100 000 gallons for the Sawyer Mini and even the measly 300L of the Platypus Gravityworks can beat this guy.) This guy can now play rear defence to polish whatever nasty bugs not removed by the Mini. Having the Mini in front also serves to remove particulates which may otherwise reduce the effectiveness of the Steripen.
  4. In actual practice, I do not place the Mini as the first man unless the water is exceedingly clear such as in an uphill jungle stream. Either I allow the water to settle first, then draw the supernatant into the Mini or I place a coffee filter before the Mini. This small and cheap accessory will prolong the life of my Mini so that it does not clog up prematurely.
  5. What I love about this setup is I can pack everything into a typical pencil case and I am ready to go. Just to restate a precaution, this setup is NOT omnipotent and does not remove chemical and radiological hazards.
Figure: The Carbon Element MUST BE fixed after the Mini to minimise unwanted bacterial growth on the GAC.

Figure: clearing up the leftover bugs with the Steripen


Unknown said...

Hi CK,
Thanks for your post, but i am a bit confuse of the eatimated damage cost for this 3 items, can advice the rough numbers pls ?

CK said...

Rough costs: Mini Sawyer ~S$30 online, Steripen ~S$120 local shop, Platypus carbon filter ~ S$30 online