On the average how much water do you all carry while on the trail? I carry about 2 liters depending on terrain exertion and heat conditions. I drink and refill when a good water source presents itself and when consuming meals. For camp I fill a 2 gallon water bag for cooking and misc. use. I always fill all my water containers up the night before and keep one in the tent while sleeping.

Wow, that really depends on a lot of things; mostly related to where I am hiking and the time of year.

When I hike in the Sierra or in the Cascades, I seldom carry more than a liter unless I anticipate a dry camp. Then, I will fill my 3-liter Platy at the last reliable water before camp. I use either a Steripen or chlorine dioxide tabs if I feel the water needs to be purified. The "Pen" will give you drinkable water in a bit over a minute.

When I hike in the Grand Canyon, I carry anywhere from a liter to two gallons. Again, it depends on water sources along the route I'm hiking and the time of year. I also carry one liter as an emergency reserve. I have used it several times; always for someone else.

When I hike the mountains of Arizona, I generally carry three liters. I know where water can be found in most of my favorite areas but like to have enough to get back to the car if a water source has dried up: and that does happen.

When I hike the desert country, I carry all the water I think I will need and a reserve liter as well. I plan on a gallon per day or more and don't travel after 10 am or before 5 pm if it is hot. Because of the weight of water my desert hikes tend to be short unless there is stone reliable water en-route.

I seldom use more than a gallon per day and dislike very much carrying an extra liter of water from one water source to the next. As noted above, I do carry reserve water in dry country and am pretty conservative about having enough water. I, too, keep a liter by my bed at night.

On a long dry trail (as per above --the desert!), we usually take a good long drink, and then take 64 ounces of water each. That's a ton of water. But it's going to be a long dry trail, and we don't like getting dehydrated.

We figure on drinking about 32 ounces of water every hour between the two of us--that's actually what most physicians recommend for exercise--so if the trail is shorter, or water sources more frequent, we adjust that accordingly.

We find we are guided by the principles:

1. WE don't like getting dehydrated. ever. It makes you slower, and stupid.

2. You don't get prizes for arriving at the end of the trail with water in your pack. Drink it. That's what it's for.

3. We pump/filter all our water--and that takes time. It's easier to pump a lot in the morning than to stop every hour on the trail, break out the pump, and go to work.

I'm with you, although I don't have two gallons in camp, but fill up the night before so I can pack and go the next morning. I see I do need to drink more water still, two quarts last me till lunch.

All depends...in the desert, 6 liters for an overnighter in cool weather (85 deg) with a reserve enough to get me back if springs aren't reliable, and allow for emergencies.
Or...when hiking along a lakeside or kayay camping, maybe 1.5 liters. I draw water as needed.

We used to come back from a three or four day trip having lost 3-4 pounds of weight...and feeling excited about that (like everybody else, we probably have a bit of weight to lose!) But when we would gain that weight back in just a day or two, we realized we were just losing water---and getting dehydrated.

Now we drink more...and feel better for it.

+ one on that. Like so many things, I had to find that out the hard way. Some year ago, while doing archaeology in Canyon de Chelly, we had climbed up to an isolated site, carrying enough for an overnight stay. We lingered on the site the next morning, frantically taking notes and photos, and became quite thirsty.

A kindly crew member met us on the descent, handed me a quart canteen, which I drained at one gulp, and I still felt thirsty.

A year later we returned to the site for more work. I brought along my field notes from the previous year. I was amazed at how inaccurate they were, particularly my estimated distances. Then and now, I attributed the inaccuracy to my extremely dehydrated condition.

most of the time 64 oz, i normally hike near a water source, if not i carry 6 liters, 2 bladders, one on each side

I usually find out what the people I am hiking with are carrying, and then double that. Even on an easy hike (1500 ft of elevation gain in 5 miles) I have went through 4.5 liters. I very rarely feel dehydrated and use a bladder/hose to make sure I am drinking constantly.

This is especially important when I hike solo because of the pace I maintain and do not like taking breaks.

All of this is personal preference of course, but I would rather take the penalty of carrying excess water than going without it, even for a mile or so.

While biology dictates our hydration needs rather narrowly as others have described, geography and climate dictate water availability on the trail. others have provided some estimates based on certain geographical and climate conditions. here is another. In all but the highest elevation of the Adirondack preserve I carry 500mL. There is water everywhere.

DTape is correct.
Growing up in a place called "waterfall valley" we never carried water except for the last "dry" 1000-1500' going to the top of a mountain (we started at 3000' and ended at 7000/9000')
(day walks)
Here in Australia I have carried up to 6 L in dry areas or where unreliable sources are.
I am convinced that drinking water is a bit like eating. The more you do the more you need. (up to a point...)
On a hike last year, (Olympic National Park) we arrived at a spot where there was a water source marked on the map however it had been sealed up and a few people around camp told us there was no water there.
I had about 1.5L left and was happy to see the night there and hike out the remaining 6-8 miles the next day with that. One of my mates who constantly drinks from a tube (20 years younger than me and supposedly fit for going to the gym 2-3 times a week) absolutely lost it because he was down to a bit more than 2 liters.
As it happen we saw some dear nearby (it was late in the afternoon) so we knew there had to be water, and found a small source about half an hour later.
BTW, I drink about 2 L a day max (outside meals) even at 100F.
Franco

You just made me feel a lot better. I'll also only drink about 2-3 liters a day in the summer, and a bit less than 2 liters in winter. I figured I was probably "doing it wrong," but didn't worry because (having been married for 40 years), I do most everything wrong.

I spend most of my free time dayhiking in the North Cascades, and am not using water for cooking. Sometimes I carry a couple Nalgenes and use a Steripen for quick, cold fill-ups, but most of the time I carry a 3 liter Platty bladder so I don’t have to mess around with water issues. Even in the summer, I usually have about a cup of water left at the end of a long hike. That said, it sure is nice to draw water from an icy cold, high mountain spring.

i usually carry a camel back 64 oz full of water if im going to be overnight in a dry area. otherwise i carry it nearly empty and pump what i need for the next leg of the trip. my pump weighs about the same as a 12oz bottle of water sooooodo the math.

3 of us went on a two day overnight tip in 90*F heat 2 weeks ago and no fill up was available so we carried and used 2.5 gallons of water. we were totally dry when we arrived at the truck!! and thirsty

If someone could tell me the recommended dosage of iodine (drops per gallon would probably be easiest for me and I was probably just going to buy it in liquid form) to treat water for drinking, I would appreciate it immensely. I made my own "particle filter" from 2 inch pvc tubing and fittings with a screw top and some holes drilled in the bottom cap using a 1 inch tall layer of cotton (bottom), a 2 inch layer of charcoal, and a 2 inch layer of pea gravel (top) and coffee filters sandwiched between fine metal screen between each layer. I'm thinking that if I treat the water with iodine before I put it through my homemade filter I shouldn't have any worries? Like I said, if someone would tell me the amount of iodine per gallon, I'd owe ya one.

Iodine is hard to find because it is used to make meth and the supply has been limited. Polar Pure is close to what you want.

http://www.polarequipment.com/directions.htm

Per the Centers for Disease Control:
"Iodine has physiologic activity (it is used by the thyroid), so WHO recommends limiting iodine water disinfection to a few weeks of emergency use. It is not recommended in persons with unstable thyroid disease, known iodine allergy, or pregnancy (because of the potential effect on the fetal thyroid)."

My own experience with using iodine to disinfect drinking water was disastrous. After a month of using it only on weekends, I developed an all-over rash consisting of deep lesions (lichen planus) that itched horribly and left permanent scars. I was also left with a permanent sensitivity to iodine: I cannot eat seafood, iodized salt (eating in a restaurant or as a guest in someone's house is difficult if not impossible) or take multiple vitamin-mineral supplements. I therefore strongly advise using a filter or chlorine dioxide tablets.

Iodine and other halogens (such as sodium hypochlorite, household bleach) do not kill cryptosporidium cysts, which are an increasing problem.

There are far less risky ways to treat your water!

I drink as much as I can when I have a water source and carry as little as possible. About 75% of the time I do not treat water that I pick up while hiking. I have never had digestion distress or any other bug from back-country water. (Cavat- I do most of my backpacking off-trail) I only carry chlorine dioxide pills. I carry two 12-oz salad dressing bottles. Most the time I only fill one. PS-I probably weigh half of what some backpackers weigh. I do not tend to get thirsty (or really mind it that much) and almost have to force myself to drink water. So I think there is a lot of personal variation among backpackers. If I drink more water, it actually just makes me pee a lot and feel worse. Yes, there have been a few times that getting to a water source was a real epic. But a few times of misery is worth nearly 99% of the time carrying little water and having the weight savings.

I've discovered that if I use an electrolyte mix (I use Hydralite, formerly known as Gookinaid, which is less sweet than most of the ones I've tried), I need less water, feel more hydrated and, most important for me, don't have to get up as many times during the night! Without the Hydralite, the water I drink seems to go right through me from one end to the other without really quenching my thirst.

I drink a lot of water--at least a half-liter--when I get up in the morning, and continue drinking while I'm packing up. On the trail, assuming several water sources during the day, I start with one liter to which I've added Hydralite (half-strength). When the bottle is half-empty, I get another liter and drop a chlorine dioxide pill into it. By the time the first liter is empty, the second liter has sat in my outer pack pocket several hours and has warmed up. I then mix in some more Hydralite. I usually have half a liter left when I get to camp, which allows me to drink up while the water obtained when I reach camp is purifying. I boil the water for dinner and herbal tea, so I don't have to wait for that. In the evening I don't use the Hydralite mix but drink plain water (I don't want to ingest water containing sugar after brushing my teeth!).

If there will be no water sources during the day, I start with 2 liters.

I have always tended to sweat very freely, even though I have a beanpole body type (currently 6 ft. and 158 lbs.). This affects my need for water on the trail, so I tend to carry a bit more water than the average hiker.

What I do carry fluctuates from 0.5 liters up to 2 liters, depending on heat and expected water sources on the trail. Unlike wandering daisy, I hate to run my water bottle completely dry and take pains not to have this happen. Still, it happens sometimes when an anticipated water source fails me. The result is usually just some mild discomfort, to which is added a lot of psychological stress I'd rather not experience. The extra water weight is worth it to me to avoid this.

It's my habit to bring 5 liters of carrying capacity, so that I can fill up late in the day and make a dry camp, if that seems best. Most of the time about 3 or 4 liters of this capacity sits empty in my pack.

I carry two one qt nalgenes. I fill one with gatorade and one with water. I premesure gatorade powder ahead of time in small ziplock snack bags. Less hassle on the trail means more fun. However if i was dry climate hiking I would carry mere, depending on reliable water sources. Happy trails