I am going to spring for a gravity type water filter this Christmas. I have seen some very derogatory comments about the Katadyn Gravity base camp filter featured in Piragis. I have seen ads about Platypus Gravity filter which seems to use a different type of filter. Any opinions about these options. thx

Derogatory comments? Here? :) I went with the MSR Gravity filter. It's nice when it's working. You just have to be disiplined to back flush it often... And that's not to hard to do.

Stay far away from the Base Camp, run run and run some more.

The gold standard is the Sawyer 4L kit, great deal considering they will replace the filter for close to free. The Platypus is also a great kit, a bit lighter and less bulkier than the Sawyer but no free filter replacement.

I have mated the two to form the ultimate system, I use the Platypus bags and hose kit, but put a Sawyer filter in for normal use, I did this before my Platypus ever slowed or clogged, I bring that as a backup to the Sawyer, I get the best of both worlds this way. The plan is to punish the Sawyer with 99% of the use, when if clogs I get to have them send me a new one. You can get the Sawyer filter in a drink bottle off Amazon or Walmart for $36 and it does qualify for the million gallon (lifetime) replacement guarantee, says so right on the box.

MSR Autoflow here.

Just started using it. Two weeks on the Yukon River which is full of glacial silt.

And another week elsewhere. No problems yet. We backflushed it once but frankly I don't know when to backflush it. We get 1.5 liters a min.

quote Ragged: "...The gold standard is the Sawyer 4L kit..."

+1

Simple. Effective. Reliable. Efficient.

I went with a Sawyer 4L in line filter.

Get some tubing and hose clamps at Home Depot.

Mate it with a couple of 10L MSR dromedary bags and you are in business.

I like to have two bags at the bottom to be able to have lots of fresh water on hand.

Also- get a priming bulb- the kind used on outboard motor boats- to backflush the system in the field when it gets clogged. and it will clog. On day 3 or four the flow really gets low.

Great system. Filtering tons of fresh water for large groups is key.

Keeps people happy and hydrated.

Looking to replace the plastic bags with these rubber ones. Sawyer filter been using it for years.


bags

This has been discussed before do a search on it, you'll get all the info and more.

JB

If you are going to be filtering bottled water or tap water from home through this gravity bag then I wholeheartedly suggest getting a Katadyn Base Camp. If you are going to be filtering water in the field, especially in the bdub, DON'T GET A KATADYN BASE CAMP...THEY SUCK!
Do the search and find what others have done. JB and a few others have some good set-ups. Do it right the first time. Don't get sucked into the base camp abyss as I did...well, unless you are looking for fodder to talked about the base camp in a derogatory way that is.

I'll praise the Hiker day in and day out but the base camp...nope, not one bit.

Have to agree with everyone else. There are a lot of good gravity filters out there, the Base Camp is NOT one of them, of course I learned that after buying one and trying to use it in the BWCA. I now use the Sawyer. Platypus and MSR seem to work well too.

...The Base Camp does make a good water bag for the Sawyer though, after you strip the Katadyne filter out of course.

...The Base Camp does make a good water bag for the Sawyer though, after you strip the Katadyne filter out of course.

+1-- had the base camp for years and replacing the filter nearly every trip got to $$. Get the sawyer in-line filter and splice into the base camp bag after cutting with a hack saw out the filter. This must be done to keep a male end on the bag.

We used a Sawyer this year. It was like having a faucet in camp. I set it up with MSR bags and hoses using a kit Sawyer has with some screw in fittings that take rubber hoses. But I'm sure their own kit would be good too.

quote andym: " It was like having a faucet in camp. "

Love that feeling

Thx for all the info-Why do some of you switch the Sawyer filter to a different bag? Whats wrong with the bags the sawyer comes with?

quote papszoo: "Thx for all the info-Why do some of you switch the Sawyer filter to a different bag? Whats wrong with the bags the sawyer comes with?"

There is nothing "wrong" with them, but some people, like me, prefer the lighter smaller less bulky bags on the Platypus kit. I also personally find the Platy bags easier to fill, but that’s simply a user preference, people with the Sawyer bags tend to be As with anything there is always a trade off, my guy tell me the heavier Sawyer bags will hold up better over time. If you could care less about an extra pound or so then by all means stick with the Sawyer bags, if you are wacky and like to try and keep your pack as small as possible go with the Platypus kit and consider using a Sawyer filter if you are worried about clogging and wrecking the filter.

I must have got lucky my basecamp worked good this summer. Albeit 7 days 3 trippers.

I picked up a platypus 4L system for about $50 this summer from the BSA supply division when they were clearancing them out.

We had 2 4L setups for 6 people over a week while doing a trip to the Sylvania Wilderness after scout camp. Like the Sawyers, it was like having a water faucet in camp! No slowdowns at all over the week, and we were up during the 7/4 heatwave when it was 110 back in Chicago. We went through 16-20 liters of water a day.

Bought a Sawyer 4 L early this year and used it for a week in the woods. Great filter, easy to use, and really liked the 'faucet' feature.

Sawyer 4L is definitely the way to go. I was a basecamp filter user which basically means you have to replace the filter after every trip (if it makes it that long).

Tried the Base Camp.....They sent me a Vario to replace it. It leaked everywhere.

Last year I bought a Sawyer and made my own. WORKS GREAT.

Last year right before Christmas they had sale that was like 20% off. Hope they do the same this year because if they do I'm going to pick up one of their squeeze systems for my solo adventures.

We used a Platypus for 9 guys this last trip for 5 days. Worked great. Just have to remember to back flush it once every couple of fills. (takes about 15 seconds). Voted the best thing we have brought in 4 trips to BWCA

I have an MSR Autoflow also, which I have never even backflushed in the field. It was pretty slow by the last day of an 8-day solo trip, but still filtered 4 liters by the time I finished everything else. I's the first thing I do when I get to camp. It doesn't bother me if it slows down because I'm busy with other camp chores and don't need it right away. The thing I like is I can just fill it, hang it, and go do other things while gravity does the work for me.

Need to edit my previous post. Last year Sawyer offered 40% off. Still hope it comes again this year.

Primer bulb - what's the best/cheapest, right size, best place to buy, etc?

quote jb in the wild: "Looking to replace the plastic bags with these rubber ones. Sawyer filter been using it for years.



bags

This has been discussed before do a search on it, you'll get all the info and more.

JB"

Same Here.

Love my sawyer 4L system. Did use the Katadyn for one trip. Worthless for the BWCA.

My only complaint about the Sawyer is it takes me two hands to operate the valve from the clean water bag. I think that could be improved.

I am interested in seeing a picture of the Sawyer matched with the larger 10 L MSR bags.

In large groups the 4L in not big enough. We usually bring along two one gallon OJ jugs with lake water in them and then poor them into the 4L dirty water bag.

Sawyer here also ! Got the 2L only regret was not getting 4L and not getting one sooner haven't even looked at the pump in 3years that's dead to me now ! I'll boil if the sawyer fails me in the BW but it won't. We also bring a 4L MSR dromebag thing too keep xtra clean water in it. That all works great for my group 3-4 guys

quote boonie: "Primer bulb - what's the best/cheapest, right size, best place to buy, etc? "

I saw one with tubing for 9.99 on boatbandit recently. Maybe it was just a Black Friday price, but worth a check.

quote papszoo: "Thx for all the info-Why do some of you switch the Sawyer filter to a different bag? Whats wrong with the bags the sawyer comes with?"

I already had the other bags.

quote schweady: "

quote boonie: "Primer bulb - what's the best/cheapest, right size, best place to buy, etc? "

I saw one with tubing for 9.99 on boatbandit recently. Maybe it was just a Black Friday price, but worth a check.
"

Yeah, they still have it for $9.99 + $12.10 shipping ;).

Maybe because I'm not familiar with this thing or maybe I'm just dense, but I don't understand how everybody is using this to backflush. Is it used separately or connected between everything? Do you need the tubing? clamps? does the sixe of this stuff matter?

TomP: I'll agree with you about the clean water bag spout. I got to where I could do it one-handed, after rigging it so that the clean bag was hanging a foot or so off of the ground (not too clearly illustrated in the pic above) but it's still a less-than-stellar design. I wouldn't want them to eliminate the 'click' in place to eliminate drips, tho.

For our family of 6, we bring two 5-gallon collapsable jugs to use for re-filling the grey bag. Pretty good system, but we still paddle out for a fresh mid-lake supply 1-2 times per day.

sorry, boonie: I'm getting used to free shipping being offered nearly everywhere this season... I think it was jb who first mentioned the primer bulb idea here ??

quote papszoo: "Thx for all the info-Why do some of you switch the Sawyer filter to a different bag? Whats wrong with the bags the sawyer comes with?"

I bought the Sawyer filter in the water bottle (same filter) and used that on the bags I already had. This also gives me the option of putting the filter back in the water bottle to use on the go for day trips.

quote podgeo: "Sawyer here also ! Got the 2L only regret was not getting 4L..."

Yeah, I just missed -- by about a month -- getting their 8L complete system. Wasn't popular enough, I guess, and it was discontinued.

Have used a Sawyer gravity the last few years. Always pumped with a Katadyn pocket filter, by far the best pump filter, and will never pump again!!! Sawyers are great.

quote schweady: "

quote Ragged: "...The gold standard is the Sawyer 4L kit..."

+1

Simple. Effective. Reliable. Efficient.


"

Sums it up for me too.

Best prices I found for Sawyer Filters is at Highwater Filters in Washington State. Check it out. I paid for mine and bought another as well.

Man you guys sure got it bad. Those filters are so slow its ridiculous, Ive got a siphon filter with a flow rate of about 10 gallons a minute, there's no fancy bag to put the water in you just use a collapsible 5 gallon bag and you have 5 gallons of running water, its so easy its almost fun. Good luck with those things anyway.

quote bjager: "Man you guys sure got it bad. Those filters are so slow its ridiculous, Ive got a siphon filter with a flow rate of about 10 gallons a minute, there's no fancy bag to put the water in you just use a collapsible 5 gallon bag and you have 5 gallons of running water, its so easy its almost fun. Good luck with those things anyway."

I'll bite, what's this filter weigh, how big is it, how much does it cost and most importantly what micron size does it filter to?

I'm curious to know which filter he is using also. The only one I found online is this one Katadyn Siphon Filter but it lists the flow rate at ~ 1.4 gal/h

quote Craig K: "I'm curious to know which filter he is using also. The only one I found online is this one Katadyn Siphon Filter but it lists the flow rate at ~ 1.4 gal/h


"

Yeah, my guess is the flow rate quoted is accurate its either going to be huge or it’s not going to filter at anywhere near the same level that hollow fiber units mentioned above. My brother in law had all sorts of nice in line filters from when he made his own biodiesel, when I looked them up they didn't filter anywhere near fine enough to get all the wee nasties, and if you are not getting the wee nasties out why filter at all.

This thing could weigh a gram, stow inside my collapsible drinking cup, and summon the aurora borealis and I still wouldn't drink from it. Just can't trust a ten gallon per minute flow. I'll stick with my sawyer.

I'll have to get you guys some pictures of this thing, its an activated charcoal filter that i made myself it uses 1/4" poly pipe and a PVC body, I take a bit of a different approach to filtering water, what i do is add a couple iodine tabs to the water then the charcoal filter completely knocks out the iodine and takes out any sediment. It's a much more effective system than anything else they have out there.

Another satisfied MSR AutoFlow user (and a former Katadyn Base Camp user...).

quote bjager: "I'll have to get you guys some pictures of this thing, its an activated charcoal filter that i made myself it uses 1/4" poly pipe and a PVC body, I take a bit of a different approach to filtering water, what i do is add a couple iodine tabs to the water then the charcoal filter completely knocks out the iodine and takes out any sediment. It's a much more effective system than anything else they have out there. "

Very interesting….. out of the box thinking, I like it, but I wouldn’t say its directly comparable considering you have to treat the water first plus you have to remember to bring enough to last the whole trip. Can you back flush the charcoal filter? I would think any filter would be susceptible to clogging if sentiment is being put into it.

I wouldn't necessarily say that iodine is more effective than anything else out there. It depends a bit on water temperature. I don't think iodine has been tested on water below 60 degrees and so while it might work at those temperatures, you can't be sure. Also, it doesn't work as well on water with a bunch of sediment in it. And you have to wait 30 minutes for the treatment to work.

So, your system goes something like this:
1) fill 5 gallon container
2) add 40 iodine tablets to it (5 gallons = 20 quarts, 2 tablets per quart for the tablets I know). If you are really using a couple of tablets for 5 gallons that might not be very effective or those are whopping big tablets.
3) wait 30 minutes
5) running water at 10 gallons per minute means you could use it all in 30 seconds. I think we can just ignore that small amount of time.

So, your effective flow rate is a maximum of 20 quarts in 30 minutes or 2/3 of a quart per minute. Or really, 5 gallons as fast as you want it after waiting 30 minutes. That's not bad.

But a Sawyer could do those 5 gallons in about 15 minutes and the flow starts immediately.

I suspect your system would be somewhat more impervious to sediment on the filtering end but more care about that would be required when adding the iodine.

BTW, I used PolarPure iodine for years before switching to the Sawyer this year. I have nothing against iodine, I don't even mind the taste much.

It's interesting to see what people come up with.

OK so as long as your not drinking out of the Mississippi river or another extremely unclean source of water you will only need 8mg of iodine per liter of water, there is 20mg of iodine in 1 portable aqua tablet, so you will need to add 8 tablets to your five gallons of water to disinfect. For water that is 60 degrees Fahrenheit it will take 15 minutes to disinfect the water, for water that is 40 degrees Fahrenheit it will take 30 minutes.

I understand this is not what it says on the bottle but you have to understand that the prescribed amount of time, and amount of iodine is for the worst situation, or drinking out of a sewer line. Anyway At maximum efficiency it will take 15 minutes for the iodine, and the filter will put out five gallons of water in around 30 seconds.

So your probably thinking ok so this is near equal to the Sawyer 4L. kit but the sawyer only holds 4 liters which is roughly 1 gallon of water so you would have to refill it five times while I fill mine once and have a five gallon capacity, and water for two people all day, this is where the efficiency of my filter really comes into play, you have five gallons of water on demand instead of one. It seems to me that it would really be a hassle to refill that sawyer 5 times a day, but hey maybe I'm crazy.

P.S. I agree it is interesting to see what people come up with.

Many on here use a hollow fiber inline filter with the 5gal collapsible containers, JB even posted a pic of his setup above, it’s not as if you can only filter from a 1,2,4 liter bag, works just as well from the 5gal container and its actually much much cheaper to go that route.


I for one would never want to filter 5 gals at a time, I just don't need that much and I like my water as cold as possible, no reason to pull 55 degree water and turn it into a 65 or 70degree water.

quote bjager: "It seems to me that it would really be a hassle to refill that sawyer 5 times a day, but hey maybe I'm crazy."

It's pure torture: Pull the grey bag down out of the tree. Remove its fill cap. Open the valve on the 5 gallon jug. Pour. Reverse process. Sometimes, you can do it alone, and maybe even with one hand if the jug is still quite full. Sometimes, it helps to have a partner's assistance.

Although I can see some advantages to bjager's system for some people and applications, there's not enough advantage for me to switch from my MSR gravity setup. I'm usually solo and have no need for more than a gallon at a time. I can't imagine what I'd need 5 gallons a day for, even if tandem. A 5-gallon container is much larger and heavier than a 4-liter bag. I wouldn't get water any faster, probably slower since I usually trip in late Sept when it's colder. It seems that it would just add time and complications, although I might get cleaner, better tasing water...?

I'm giving consideration to just going with a Steri-Pen and 2 2-liter Platypus bottles for solo trips.

I am curious how many people find five gallons of water for two people a day a necessity?

Now granted we are only one or two. We do not tend to canoe with big groups, but one gallon of water a person a day for all uses seems to be sufficient, even when we have no fresh water available (like on the ocean) Between the two of us we find that we only need to filter for drinking water..and that usually is less than a gallon of water for two.

My Sawyer is attached to a 10 liter Sea to Summit camp sink. This gives us about 2.5 gallons, which for two people is plenty for a day. When with more than two people, we just fill the "sink" twice. And filling is simple- dip bag in lake/river, hang, fill containers as needed. Because the camp sinks have such a wide lip and handles, filling is a simple scoop. With this system I get a fast enough flow to be able to hold my Nalgene while filling. Never timed it, but it probably takes around a minute to fill the 32 oz bottle, so not really any waiting around for potable water. Also, no need to lug around huge jugs of water while on the move- it can be pulled out in the middle of a lake or at the end of a portage trail to refill our bottles (not much fun to hold the bag up while refilling, but it is possible). This rolls into a palm sized bundle and weighs right around 10 ounces, including tubing and plastic plumbing fittings. Granted, what works for me may not work for everyone, but I doubt there's a more efficient system out there.

Our group of six went through about 30 gallons in a 3-night basecamp last August. Talked afterward that we probably should have drank a bit more... Came up with 2 gal per person per day as a good volume to shoot for.

quote schweady: "Our group of six went through about 30 gallons in a 3-night basecamp last August. Talked afterward that we probably should have drank a bit more... Came up with 2 gal per person per day as a good volume to shoot for.
"

I assume that's for all uses and not just drinking...? Two gallons seems like a lot to drink, even working hard on a hot day.

Oh and another advantage to my filter cost me about 15 dollars to make, and was kind of a cool little project. So for the group that wants to have a large amount of water ready for use this is the way to go. Hearing some of the comments it seems some people think it is terrible to filter 5 gallons of water in a day, why is that? I think its actually nice to have 5 gallons at my disposal, I don't have to conserve water, or live with the minimum daily amount. I can drink it, cook with it, brush my teeth with it, and only fill it once a day or maybe less.

quote boonie: "

quote schweady: "Our group of six went through about 30 gallons in a 3-night basecamp last August. Talked afterward that we probably should have drank a bit more... Came up with 2 gal per person per day as a good volume to shoot for.
"

I assume that's for all uses and not just drinking...? Two gallons seems like a lot to drink, even working hard on a hot day."

Yeah, we'll use the filtered stuff for making coffee, cocoa, gravy, milk-based recipes... stuff that lots of folks would say is unnecessary because even though it's not boiled it's still heated. But it makes the wife happy. Ergo I am happy. About the only unfiltered use is washing.

We have had one too many scary moments on trips due to dehydration, so push the liquids pretty hard.

quote bjager: " Oh and another advantage to my filter cost me about 15 dollars to make, and was kind of a cool little project. So for the group that wants to have a large amount of water ready for use this is the way to go. Hearing some of the comments it seems some people think it is terrible to filter 5 gallons of water in a day, why is that? I think its actually nice to have 5 gallons at my disposal, I don't have to conserve water, or live with the minimum daily amount. I can drink it, cook with it, brush my teeth with it, and only fill it once a day or maybe less. "

Don't get me wrong, bjager - I don't think it's terrible to filter 5 gallons of water a day, just not necessary for me. I don't conserve it or live with a minimum amount - that's just what I normally use for drinking, cooking, etc when I'm solo. If I need more, it's not too difficult to dip the dirty water bag in the lake, hang it, and do something else for 5-10 minutes. I usually travel every day and I'm not going to carry the 4 gallons (32 lbs.) of water that are left over so I'd just end up dumping it, which would be a waste of the iodine used to purify it. Nor am I going to carry water storage that's 5X as large heavy, and bulky as I need. Were I to start over and make myself a solo system like yours, I'd design it as a 4-liter system. The price is certainly right.

It would make a lot of sense for a basecamping group of nine like Schweady's group to have a 5-gallon or even larger system.

Good point that the usual dose of iodine is probably overdoing it in most circumstances. Where did you get your timing for different temperatures of water. The polarpure site says that the FDA hadn't tested adequately below 68 degrees but that could be out of date or there could be other sources of testing.

I wouldn't mind a larger container for the water and was just using the 4-liter one because it is light.

quote bjager: " Oh and another advantage to my filter cost me about 15 dollars to make, and was kind of a cool little project. So for the group that wants to have a large amount of water ready for use this is the way to go. Hearing some of the comments it seems some people think it is terrible to filter 5 gallons of water in a day, why is that? I think its actually nice to have 5 gallons at my disposal, I don't have to conserve water, or live with the minimum daily amount. I can drink it, cook with it, brush my teeth with it, and only fill it once a day or maybe less. "

But at the end of the day it’s not an apples to apples comparison, your end product is not the same, it’s not filtered to .1 micron and it has to have chemicals added, and even then to reach your stated performance you are deviating from suggested practice and going into uncharted and untested territory, which is completely fine, but again it’s not really a fair comparison and it doesn’t offer the peace of mind that you get when you use a fully tested filter set up, in my eyes you are somewhere between taking it straight from the lake and using a fine micron filter, but that’s just my personal take on it.

I’ve never once rationed water, I drink as much as I want, I cook clean and wash my hands with filtered water, I do nothing with dirty water, and still I just don’t ever need 5 gals at a time for 2 people. I actually enjoy the whole process, if you back flush often you can easily filter 4 liters in 3-4 mins, I can have 10 liters of clean filtered water and another 4 liters of dirty on deck and the whole deal may take 15 min tops, and 80% of that time you are free to do other camp choirs like pitch a tent or look for the thunderbox. I’ve just never once gotten to camp and said gosh darn it, I need 5 gals of water and I need it NOW, I mean what are you doing, taking a bath? Washing the Canoe? Lol


A couple liters to chug down after cutting wood, a couple liters to get food going, then a couple liters after meal to wash up with, that’s 6 liters and that’s being very conservative, I don’t use 2 liters to wash my dishes, hell I don’t even have dishes most of the time, just a utensil. 6 liters and I still have 2 on deck for evening drinking, haven’t even busted out the 6 liter tank in this hypothetical (yet very typical for me) scenario. It’s great that you have a system that works for you but I just don’t think the wool is over our eyes as much as you think, and if you are worried about cost get a Sawyer, buy once and they are $5 in shipping costs away from having a new one whenever you want.

Not sure how many tablets come in one, but those tiny bottles of iodine tablets average about $10, so there is definitely a recurring expense involved. If we're talking about using 8 at a time, it can't take too long to empty a $10 bottle...

For me, and I believe others on this board, the entire gravity filtration system cost as low as $40 to put together and should last a lifetime (at least when considering Sawyer's 1,000,000 gallon warranty). My folks used to teach me that what's cheap today ain't always cheap tomorrow. Why buy the $200 Ford Pinto when you'll have to replace the engine next week? The $20 inline Sawyer is the Honda of filters.

Interesting thread. I've opted to go with and highly recommend the Platypus 4L gravity system. I've added a second 4L Platypus water tank so I can have 8L available. This works fine for 4 people. Filtering water is just one of the activities that I enjoy in the BWCA. It beats being at work getting water from the office cooler.

Ragged, would just like to let you know I am currently the president of a well service corporation, and have experience with water conditioning, so I am very confident in my filter and I do have peace of mind when using it. Anyway please explain how iodine treatment is at all uncharted, untested, or not suggested. Maybe you don't understand how this system works I'll try to break it down for you.

1. The water is treated with iodine and is already safe but has an unpleasant taste, sediment, and other impurities.

2. The water is then siphoned through the activated charcoal filter, and all traces of iodine/sediment are removed, making the water a lot more drinkable, and great tasting.

If you are worried about something getting past the filter, which is nearly impossible it would be harmless because it has been disinfected with iodine. And also because the iodine is removed by the charcoal filter you are not drinking any chemicals, just clean water.

I use more water than the average man as was pointed out to me in previous posts, but then again I don't have to worry about water usage because I have 5 gallons ready to go, anyway you said that you do not need 5 gallons of ready to use water, I already stated "for the group that wants to have a large amount of water ready for use this is the way to go" obviously you don't need it as you stated, but for larger groups (yes you can have more than 2 people in a group), people who like to do things their self , and people that like to have more water at their disposal this is a great option, and learning experience.

Intrekid, each bottle of portable aqua iodine tablets contains 50 tablets, the price varies between $6.00-$9.00 a bottle lets say you use 5 gallons of water a day, for ten days you would use less than two bottles.

andym, check this out, http://www.high-altitude-medicine.com/water.html

quote bjager: " Anyway please explain how iodine treatment is at all uncharted, untested, or not suggested. Maybe you don't understand how this system works I'll try to break it down for you.



If you are worried about something getting past the filter, which is nearly impossible it would be harmless because it has been disinfected with iodine. And also because the iodine is removed by the charcoal filter you are not drinking any chemicals, just clean water.


I use more water than the average man as was pointed out to me in previous posts, but then again I don't have to worry about water usage because I have 5 gallons ready to go, anyway you said that you do not need 5 gallons of ready to use water, I already stated "for the group that wants to have a large amount of water ready for use this is the way to go" obviously you don't need it as you stated, but for larger groups (yes you can have more than 2 people in a group), people who like to do things their self , and people that like to have more water at their disposal this is a great option, and learning experience.


Intrekid, each bottle of portable aqua iodine tablets contains 50 tablets, the price varies between $6.00-$9.00 a bottle lets say you use 5 gallons of water a day, for ten days you would use less than two bottles.

andym, check this out, http://www.high-altitude-medicine.com/water.html"

I understand your idea 100%, and I'm not inferring iodine is untested, I'm saying deviating from the prescribed directions is a little untested. You said you reduce the recommended number of tablets because the water quality dictates it it, to me that’s a bit of a judgment call and an opportunity for something to happen, last I checked you can’t see bacteria, hopefully there isn’t a dead bloated moose around the bend or a beaver up a nearby stream. You are leaving the recommendations on the package in favor of a personal call which you are likely qualified to make, but that does open a window for issues, especially for someone like myself who knows next to nothing about judging water quality. I fully understand that there is probably little to no risk in making that call but it’s still a judgment made by you.

Also it’s not about using 5 gals a day, it’s about using 5 gallons in a matter of 30 seconds to a minute, you can get 5 gals from a Sawyer filter with no issue, just takes 15 min or so.

The cost would seem to be much higher for your setup, some of these diehards take many trips per year, they could be spending $10-30 on tablets a year vs a Sawyer filter that you buy once for $35 and use forever.

I'm not saying one set up is better or one is right for everyone, I just keep getting this feeling (started with your first post) that you think we are all clueless and that you have figured something out that we haven’t, and well I don't see that to be the case., that’s all : )

bjager: I don't think anybody here is missing your point or not understanding how your filter works, but I do think that you may be missing our point. I think Ragged has got it right in saying that you haven't figured out anything that we haven't. Collectively, you are talking to hundreds of years of outdoors experience.

I am honestly not sure about Katahdin or Platypus filters, but my Sawyer filters 99.99999% of impurities. That is almost the equivalent of saying that every gulp I take is 99.99999% hydrogen and oxygen. Essentially, pure water. Your system may be a fun project, but it just doesn't provide any benefit that we aren't already getting. 5 gallons on hand- see jb's system. Cheap- not really when you consider paying for iodine and replacing your charcoal over the years. Speed- by the time your iodine has done its work (15 mins @ 60 degrees), I am already hydrated with camp set up. Size/Weight- not sure how yours measures up. Clean/Safe Water- not as clean as mine.

from How Stuff Works: "Activated charcoal is good at trapping carbon-based impurities ("organic" chemicals), as well as things like chlorine. Many other chemicals are not attracted to carbon at all -- sodium, nitrates, etc. -- so they pass right through. This means that an activated charcoal filter will remove certain impurities while ignoring others. It also means that, once all of the bonding sites are filled, an activated charcoal filter stops working. At that point you must replace the filter." As far as I know, my filter doesn't ignore any impurities. Also, high levels of nitrates in the blood system can lead to some serious health risks...

Carbon filters are used in fish tanks- would you drink aquarium water? I wouldn't, unless it had been run through my Sawyer. A ten gallon/minute flow means that must be some pretty porous charcoal and/or a lot of pressure pushing the water through. There are bound to be some sizable nasties passing (or being pushed) through those pores. While the iodine may have killed bacteria, you're still drinking moose/beaver/loon dung particulate. Now if you slow your flow to say 1 gallon/minute, your carbon will be much more effective, but by having to wait on your iodine to work, you're process is already time consuming enough.

I understand wanting to do things a certain way, and I can appreciate that. Hell, I use an alcohol stove that takes way longer than my buddie's JetBoil. But guess what? I'm gonna use my Trangia because I like it and I want to. And while I might try to preach the benefits of alcohol cook systems to non-believers, I know that by the time my water boils the JetBoil user will have already finished drinking their first cup of coffee. Much like how I will have finished gulping down my fresh, clean water while you're still waiting on your chemicals to clean yours.