"Waiting more than 30 minutes for the pills to work is a bit more than I want to wait, and if it is even longer for cold water, what's the point of using them? How religiously do any of you who use the pills wait the full 30 minutes or much longer for cold water? "

That's a big reason why many folks use Steripen or filtering instead of chemicals.

Back in the old days when I used iodine to treat my water, I always carried two Nalgenes. Bottle A, my drinking bottle, had water which had been treated more than 30 minutes before, at the next to the last water source. Bottle B, the treatment bottle, had fresh water from the last water source plus iodine. Hopefully Bottle A was about empty when I got to the next water source, where I refilled it and added iodine, and Bottles A and B would switch roles. That way I always had warm, nasty tasting - but clean - water to drink!

I love my Steripen!!!!

I try to plan my water sources just in time. Once there, I cook a meal which boils some of the water and chemicals go into the rest. Other times, I will be drinking the last of my water at the source, and there is time to wait for the rest to work with the pills.

Never owned a filter or other heavy mechanism that might malfunction :)

Did you drink any non municipal water supplies in the last month. I got crpyto when i was a kid from farm well water that was contaminated and was just using a sand filter.

I am debating quiting treating water, i certainly dont hit the required wait times for clo2 tablets. Might just get a sawyer squeeze for lakes.

It would be nice if the EPA would furnish a few intermediate numbers for estimating contact time for conditions between the two! For those of us who backpack in the high mountains, water from springs is likely to be in the 30s F but is usually clear. It's obvious that the 4 hour wait time on the package is the absolute worst case scenario.

A good rule of thumb for chlorine dioxide (ClO2) would be to double the time for each 10° C decrease in temperature. As the Katadyn chart suggests 30 minutes for clear water at 68° F, that would indicate a one hour treatment time for 50° F water. This assumes, of course, that there is no padding that built into that 30 minute time.

Note also that ClO2 will also react with organic matter in water, lessening its effectiveness.

Ref: (relevant content starts around page 646)
www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA449339

If you can't or won't wait for the chlorine dioxide pills to do their job (those cysts are hard to kill!), I strongly recommend using another method. Giardia cysts are less resistant to chemicals than cryptosporidium cysts, but not much. There is a good reason for those long wait times, as you've recently discovered the hard way. See Jeremy's link just above.

Not all filters are heavy and clunky. My homemade gravity filter (using a Katadyn Hiker Pro replacement filter and vaguely based on the now defunct ULA Amigo Pro) weighs 6.6 ounces, which is far less than the weight of an extra liter of water undergoing chemical disinfection. During a 5-minute break I can filter a liter of water, drink half of it, and carry only the other half liter. The water tastes better, too! Of course this weight comparison is valid only where there are frequent water sources, but that's mostly the case where I backpack. If you normally go all or most of the day without water sources and have to carry two liters anyway, the weight advantage of course goes to the chemicals.

For more info on various MYOG gravity filters, go here--there are several versions:
http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=8994
Mine is the one that starts well down on page 2, in the post by Cola Vaughan. (Cola, if you're reading this, thank you!) No moving parts to break and no pumping.

I haven't used the Sawyer squeeze filter but have heard good things about it. It weighs half as much as my gravity filter system, so I plan to check it out.

Edited by hikinggranny on 04/25/2012 19:44:48 MDT.

is that my 9 oz gravity filter is completely justified. Also, doubles as my hydration bladder.

I agree with Mary (and others) above. If one does not wait the necessary time for chemical treatment to work, why use any treatment at all? May as well forgo the 2 oz of chemicals and tiny vials. This is BPL after all.

-Jeff

"If one does not wait the necessary time for chemical treatment to work, why use any treatment at all?"

You can do the chemical treatment and then rush the wait time. It still may be effective, but you are taking a much bigger risk. It is all a compromise.

FWIW, I use a gravity filter with a 2L Platypus above and another 2L Platypus below. Then, if I want to reduce risk further, like if the water looks bad, then I have a small amount of chemicals to use for overnight wait.

--B.G.--

Thank you Jeremy for that reference. I have been wading through it, and although dated 2006, it contains a lot of current devices.

Interestingly, it scores Aqua Mira lower than Micropur despite both being based on ClO2, although both are deemed adequate (pages C-71, E-59-3, E-60-3). However, they use the products as instructed by the manufacturers, and a 30 min wait time is specified for AM, but 4 hrs for Micropur, despite similar concentrations of ClO2 being produced. I wonder whether Micropur would compare as well as AM with only a 30 min wait? Probably the test will never get done (or Katadyn will never tell us). For cryptosporidium it says wait 4.5 hrs with AM if <10'C.

There's a specific discussion of both Micropur (p 488) and Aqua Mira Drops (p 494); It appears that the main differences were that test data was available for Micropur, and that the manufacturer instructions for the drops specified only 30 minute disinfection time (that's why crypto wasn't checked off in the charts). They do note in the discussion that the drops are likely effective against crypto if you extend the wait time to 4.5 hours, similar to with Micropur.

(So, it looks like more of a "paperwork" difference.)

Filtering, chemical treatments, UV treatment, or boiling.
All have good points and bad points.

Chemicals (chlorine dioxide, iodine, bleach to name a few) don't work on all everything. They are all based on some statistical measurment. Even following directions you can become infected. They DO NOT WORK on some tapeworms.

Filters dont work on everything. Again, ststistically based unless you get a good fine filter, then they are too slow for any camping.

Boiling works on anything except chemical contaminants. It *may* make these worse and adds to fuel usage.

UV is supposed to scramble DNA, again statistical.

So, really, you just rely on your body to deal with the large amount of bacteria and parasites present in any water. I would not worry too much about it. Use whatever you like and do the best you can.

The Aquamira drops make no claim to being effective against Giardia or Crypto, as opposed to the tablets, which DO make such claim right on the package. But the drops also only require only a 15-30 minute contact time, whereas the more concentrated tablets require up to 4 hours in order to deal with the Giardia and Crypto.

The majority of folks that use Aquamira on BPL seem to be using the weaker liquid and wait at least 15-30 minutes (per the instructions), AND they generally don't seem to be reporting that they got sick. In threads about giardia and crypto, folks routinely say things along the lines of, "As long as I've treated my water with the drops, I've never gotten sick."

But is it safe to assume that since they weren't using a product proven effective against the cysts at the short, recommended contact times that the reason they didn't get sick was NOT because of the efficacy of the product but rather because there wasn't any Giardia or Crypto in the water to begin with? Am I off base here?

Katadyn MicroPur tablets were EPA registered as soon as they hit the market back in abouts 2005 or so. Aqua Mira drops were around before that time, but have only been EPA registered in the last couple of years. In the past it was thought that the MicroPur tablets were double the strength of the AM drops, but that may not be the case.

No difference in concentration between Aquamira drops and tabs. Here's a link to the thread where Dan Durston reiterates this, and links to a letter from Aquamira COO (also posted on BPL forums) spelling it out in detail:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=59824&startat=20

I stand corrected, so thanks David for that info. I had gathered that there was a concentration difference between the liquid vs tabs from other threads on BPL, which I'm sure you've seen.

I would submit, that there is a combination effect, also. You may have some partial resistance. Soo, things like 5 or 6 gardia organisms do not effect you. If you have a weaker digestive system, your partner may contract it. Difficult to verify anything, especially when there is quite a long and variable incubation period.

Different varieties of the same organism will effect the onset of a disease. Some will react strongly within four or 5 days and sick for 4 weeks. Some will be a little loose for a day. Difficult at best to diagnose and establish. There are too many variables. IFF it becomes of fatal or serious consequnces, there will be an EPA investigation...if they have the money, ha, ha. Our parks, waters and other lands are being raped in the name of the economy.

Perhaps this could be helpful,http://www.cdc.gov/healthywater/drinking/travel/backcountry_water_treatment.html

Mitch, nasty stuff and I'm glad you brought it up.

I've never had Beaver Fever, at least from the water to my knowledge, but I have had a gnarly C.Dif infection that nearly ended rather poorly for me. Similar to Giardia, this one's a cystic infection (mentioned above) and one of the keys to combat it, before and after antibiotics like Flagyl or vancomycin are used to kill them off, is the introduction of gut flora like the stuff you're taking.

I still regularly ingest probiotics in "regular food", like kefir and other such stuff, and in supplements like Yakult, because I have great incentive to prevent a reinvigoration of the cystic infection. There is genuine science out there to the effect that our immune system is much more resistant to cystic infections when we've got a gut full of the right flora, so I recommend family and friends who are backpacking to use probiotics in preparation for their trip, presuming they don't do it regularly already.

It's not a bulletproof shield, but having vibrant intestinal flora is proven to improve our bodies' ability to combat water- and food-borne illnesses. Guys like you, who've had Giardia, give good reasons why it might be better "to be safe than sorry".

You know I have been taking acidolpholus for years in massive doses and perhaps that accounts for the fact the my case of giardia was milder than I could have expected. Who knows, but I do agree that I seem to be a healthier person for taking it regularly and certainly during and after this case of giardia.Often when you take antibiotics you end up with diarhea and/or constipation. I never have.

Unless you are drinking out of mud puddles like my dog, I think direct person to person
transfer is more common in North American.

Follow your Grandma's advice. Wash your hands after the toilet and before you eat.
Giardia doesn't require the incysted form to be shared.

"An outbreak of giardiasis was investigated in one urban day care center; another day care center was selected as a control. In the study day care center, 35 per cent of the children were infected. Infection was spread to at least one household contact of 47 per cent of the infected children. The data suggest person-to-person transmission of giardiasis and the need for measures to prevent its dissemination. Early recognition and treatment of Giardia lamblia infections in children may be indicated."

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1646578/

Edited by oware on 04/27/2012 12:48:17 MDT.