I'm planning to take my first ever hiking trip next week, weather permitting. The trail winds around a lake.

I'm not planning to take a water filter, just some Potable Aqua tablets. I'll have to dunk my quart-sized water bottles into the lake in order to fill them up.

A couple questions. First, do I have to be so paranoid of bacteria and viruses that I need to wash my hands off with sanitizer gel after coming in contact with the lake water?

Second question, I've never looked at lake water too closely but I imagine there will be some particulate matter. I'm not really interested in drinking that. I thought I could try fixing a coffee filter around the water bottle to filter out the larger particles. Does that sound reasonable or is there a better way to do it?

A few years ago I thought I'd see whether all the filters and treatment pills were necessary and spent a week canoe camping on a lake in eastern Arkansas (where camping isn't technically allowed) in August. I used lake water, which at that time of year was pretty green and even had chunks of stuff floating in it. I boiled everything ten minutes before using it for drinking or cooking--added cooking time to that. By the end of the week I had some minor intestinal problems which went away without treatment after about a day, and I'm thinking now that it could have been cross contamination from the containers I used for hauling water, or maybe just from water I ingested while swimming. The water looked pretty bad, you could put an arm into it and have a hard time seeing your fingers.

I'd probably not do that again, it was just an experiment. I've read various things about how dangerous the water is, cryptosporidium is maybe the toughest thing in it to kill. The government still says boil water for a minute to kill it, and it may not be affected much by water purification tablets. Other people say you have to boil for ten minutes to kill it, and I'd go with that, better safe than sorry. Ceramic filters that take out one micron particles are supposed to be good enough to drink from. I usually double up, use a good filter and then boil the water.

I wouldn't be at all concerned about drinking lake water that was filtered and boiled or filtered and treated, but I think I'd plan on being really sick for awhile if I drank much of it straight.

Getting the big chunks out, the things you can see, is easy enough. Cloth or a coffee filter will do that. You might try wrapping a water bottle top with the filter and just submerging the whole thing instead of trying to pour anything through the filter.

I didn't find that the chunks affected the quality of the food much, most of the big stuff floats.

OK, here's my iodine warning which I post a couple of times per year.

After using iodine to purify my water on weekends for about a month, I came down with a horrible rash. It consisted of deep lesions (lichen planus) which left permanent scars. To this day, 22 years later, I cannot tolerate iodized salt, sea food or vitamin/mineral supplements (nearly all of which contain iodine). This prevents me from accepting invitations to eat out (nearly all people use iodized salt for home cooking, and so do most restaurants). Should I ever have to have a medical diagnostic procedure using iodine (i.e. angiogram)--well, I'll just have to die of the undiagnosed disease! I found since that allergies to iodine are quite common. Iodine is contraindicated for pregnant women and small children (which should tell you something about it) and is recommended by the CDC only for emergency purposes.

Chlorine dioxide (Aquamira or Katadyn Micropur) is much safer than iodine--that's what's used in municipal water systems. However, like iodine, it requires a long contact period--up to 4 hours if the water is cold--to kill protozoan cysts (giardia and cryptosporidium).

Even a heavy filter is lighter than the boiling option, which requires a lot of extra fuel. Boiling also requires a wait for the water to cool down, and the resulting water tastes pretty awful.

I personally use a filter, but take along Micropur tablets for backup (filters can break, and the tablets weigh hardly anything). If the water source seems really suspect (contaminated by livestock or downstream from human habitation), I'll use the tablets in addition to the filter to kill viruses, which filters don't remove.

Growing up my dad and i boiled all our water. As i found out this is bad for ultralighters because of the extra fuel. I was going to use iodine pills but a friend told me that it was bad for the liver over time. Chlorine dioxide might also be bad for the liver over time, but the fact that lots of water for the public is treated with Chlorine dioxide i would assume it is safe. PLus it doesn't taste as bad.

I have gone whole hiking trips on the PCT without filtering, thought this was when snow was melting. My rule on treating or not treating is if i can see where the water has traveled and if it hasn't gone threw a flat field where cows could possibly roam then i dont filter or if the water is clearly snow melt. I rigged up a screen that keeps the big floaties out. If i dont know the area where i am hiking i always bring a filter and Chlorine dioxide. That me, and i have never caught a bug.

Most places I treat my water with Chlorine Dioxide treatment (pristine, or aqua mira brand). I don't carry a filter. I've drank enough bush water I'm conditiond to not care too much about chunkies and chewies, they don't bother me too much if it's really thick I'll use a shirt or bandana to filter the large bits out.

If I were expecting to have to draw water out of a mud hole full of cow patties, I'd probably carry a filter.

Don't worry, I read a previous post about iodine, so I purchased the chlorine dioxide tablets instead. They work great, but I discovered the hard way that the four hours the tablets require to work is too long to wait.

The coffee filter trick didn't work too well, because it seems water has to be forced through the filter. Or maybe you have to wait a really, really long time for it to drip through.

I'll definitely switch from tablets to a water filter... although I'll keep the tablets for backup, as they do work well, and leave the water tasteless.

Thank you everyone for your responses. I was just looking at my filter today and reading the manual (Yes, I figured it was that important to actually read it). I found the section where it pointed me to the CDC website on water treatment methods. This saved me a duplicate posting.

I have been thinking about doubling up and filtering and treating. The four hour wait is not to desirable, but I really don't want to spend the extra time in the bathroom or digging holes.

I think the important thing to remember here is that this is critical. If other backups like filters and tabs fail, or the water you're working with is too nasty to trust to that, boiling is the thing that works even if you have to spend fuel and time to do it. It doesn't mean extra weight in carried fuel, we're smart enough to build fires and use them safely. Boiling is the last resort and also the dependable failsafe method the CDC recommends, and I make sure I'm safe by adding anything else to that. Boiling may be the last thing in the chain, but it's the last thing I'd give up. If I have to build a fire to boil something, I'll do that.

Jimmy TH

I appreciate your comments. And, I would add....Filters don't filter out Viruses, they can't by definition. And, tablets or Iodine take a long time (hours) to work if the water is cold, as it always is here in the northwest. This is a fairly complex subject. Colin Fletcher and Chip Rawlins do a good job of explaining it in The Complete Walker IV (pages 237 to 252).

I tend to boil water if I do anything. I have drank plenty of untreated/unboiled water an not experienced any adverse consequences. I just try to pay attention to where I am getting it from, if I have a canoe, I get it from the middle of a larger lake, the UV kills a lot of the bad stuff. Also, side note: the whole debate about how long you need to boil stuff is moot. Once you actually get water to a boil, it will have been at sufficient temperature long enough to kill anything living in it. Boiling something for 10 minutes doesn't get it any hotter, boiling water is always 212 degrees F (give or take 10 for altitude and impurities), it just wastes fuel.

That being said, I am looking into a good filter to get rid of most of the crap (visible and invisible).

At 10,000-11,000 feet, normal camping altitude in Wyoming or Colorado or California's Sierra, the boiling point is about 190 degrees F--significantly lower! The time the water is above 180*F and killing things is far shorter, so you do need to boil (or simmer) longer!

Note also that protozoan cysts are a lot harder to kill than bacteria or viruses.

In high altitude conditions, a minute or two long boil may be necessary to kill everything according to Princeton University.

I typically don't take much elevation into account because I typically don't deal with very significant fluctuation from sea level. Generally speaking (~1 atm), the water will have been hot enough for long enough once it has been brought to a boil and cooled.

My bad, I did not provide for significant elevation differences.

That's why it's great to have folks on this forum from all parts of the country--if one of us generalizes too much (I do, too!), there's someone with a different perspective to set us straight!

I personally prefer not to boil water. You have to wait for it to boil, then wait for it to cool, and it tastes really flat. Boiling is really a pain if you replenish your water during the day (which I do when backpacking where there are frequent water sources). I prefer to filter and then, if the source is really questionable, use Micropur tabs to kill off anything that might have been too small for the filter to remove. The big stuff (giardia and crypto cysts) will have been caught by the filter, so 20 minutes' time for the Micropur treatment is more than ample to kill everything else. I particularly do this if the source is stagnant ponds used by livestock or frequented by herds of wild game (such as elk). I purify my dog's water in that case, too, because such water sources can be a source of leptospirosis. Yes, there is a vaccine for dogs for lepto, but it's not very effective and causes lots of reactions. It's better to keep them out of stagnant water. Humans can catch lepto, too.

Oregon, I just purchased a Katadyne Hiker water filter. REI, Had them on sale for 44.00 bucks last week. Do I need to use purification tabs as well with this filter? I didnt think I did?

Only rarely would you need to use the tabs on top of the filter. The filter takes care of protozoan cysts and most bacteria, but not viruses. I only use the purification tablets when the water source is really horrible--as I said, stagnant ponds trampled by livestock. If you have to use river water downstream of human habitation (which might have virus contamination), that would also be a place for the tabs. I carry the micropur tablets mostly as a backup in case something should happen to the filter. The weight is nil and having them means I can finish my trip should the filter be lost or damaged.

I made a quick video on why you should allways filter water, Enjoy

Why Filter Water ?

Some good stuff on there, Peak.... Thanks for posting!

Never new tampons were so useful in a survival kit.