Jul 25, 2009 at 10:17 am #1238071
I've done some searching but haven't really been able to find what I'm looking for so forgive me if this has been covered a dozen times :>
How do you deal with SUL water carry? Seems to me I would have to carry 2L of water at a time? One to drink while I wait 4 hrs for the other liters chemicals to work? When I read some of the SUL hydration methods some use, it seams they only carry 1L average? How is that done without some instant method for treating like UV or a filter?
I'm trying to keep my hydration system as SUL as possible. Trying to decide between carry 2L and use chemicals only vs. carry 1L and something like a Steripen adventurer?
Am I missing something?
BarnettJul 25, 2009 at 10:52 am #1516452
@jshorttLocale: North Carolina
Barnett, I tend to only carry 1 liter of less at a time. I use MicroPur tablets for purification. As long as the water source looks reasonably safe I only wait 30 minutes. I try to plan my water so that I am out before arriving at a source. I stop, collect water, drop in a tablet, check my watch and off I go. As soon as 30 minutes is up I drink.
There has been a lot of discussion on the wait time for these vs aqua mira, but based on what I read decided 30 minutes was good enough for me. Its worked so far.
I will say that I have waited as long as 2 hours when I thought the water was questionable. Most of my hiking is in NC and VA.
JamieJul 25, 2009 at 11:06 am #1516456
I've only ever waited 30 minutes with Aqua Mira and I've been fine.
I carry 2 one liter platy bottles.
I drink one down…when it's getting low, I fill and treat the other and keep leap-frogging them throughout the day. If water is scarce then you just fill both.Jul 25, 2009 at 5:33 pm #1516510
Thanks for the comments. I should have mentioned I'm in the North East. It sounds like those using chemicals are only waiting the 30 minutes to kill bacteria & viruses, not the recommended 4hr wait time to kill Crypto or Giardia?Jul 25, 2009 at 6:35 pm #1516519
@sm498Locale: San Francisco Bay Area
As I understand Chlorine Dioxide:
Warmer temperature means a shorter treatment time. I think MicroPur is speced for 70 degree water. If the water is 88 degrees, you don't have to wait as long. I remember an old rule of the thumb from chemistry that increasing the temperature 10 degrees C doubles the reaction rate. So, I figure that 88 degree water only needs half as long to treat. Conversely, 52 degree water would need twice as long.
You can adjust the treatment time and dose over at least a factor of 2. You can use a double dose (two tabs) and wait half the time or you can use a half dose and wait twice as long.
There is already a significant safety factor built in to the recommended dose, so you don't have to add your own safety factor to the manufacture's safety factor
You could consider using a coarse filter to get the cysts (Giradia & Cryptosporum) out of the water.
I hike in dry places, so the water often looks like a food source. I'll filter through a bandanna to get the big floaters and small swimmers out of my drinking water and then treat it with a double dose. If I have any question about the water possibly containing cysts, I'll wait at least 2 hours (with a double dose).
Here's a somewhat technical reference. They say that an 10 degrees C increase in temperature increases the inactivation rate by a factor roughly 3.
from the document above commenting on crypto (which is tougher than Giradia) "Based on a typical chlorine dioxide dosage of 2.0 mg/L for a water system, contact times of 115 – 915 minutes (2 – 15 hours), depending on temperature, are necessary to achieve the CT values in Table 3."
Note that organic matter and silt in the water will "soak up" the chlorine dioxide before it gets a chance to inactivate cysts. I also don't know what the ClO2 concentration is from one tablet of MicroPur.
"The CT is the product of disinfectant concentration (C in mg/L) and contact time (T in min)."Jul 26, 2009 at 10:10 am #1516598
Thanks I appreciate the inputs & did some more searching as well. I've decided to go with the CIO2 tabs & the 30 minute wait general rule. I settled on the following setup below. I'll usually just use one Platy, but will carry the second if I need to haul a second liter for dry stretches or for extra water in camp.
Two 1L Platy Bottles with Poptops .99oz ea.
1L homemade Platy water scoop .5oz
Homemade Platy cap/Wire coffee screen Filter .09oz
Ten CIO2 Tabs .22oz
Total = 2.79oz
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