How to Purify Water Using Iodine Tincture




About: I like sleeping far too much for my own good.

When you're in the wilderness, you need clean water to drink -- but water sources in the wilderness can carry bacteria such as giardia. You don't want giardia, trust me, and trying to carry a few jugs of Poland Spring would be extremely heavy and inefficient. Luckily, there are a number of ways to purify water, and one of the simplest, cheapest, and most effective ways is to use iodine tincture.

Step 1: Supplies

To complete this task, you'll need the following:

--Water bottle: A Nalgene (what I use here) or a metal water bottle will work best, but all you really need is any container that will hold water.

--Iodine Tincture Solution: You want Iodine Tincture with 2% Iodine and about 47% alcohol. Bottles of this solution should be available at your local drugstore and a 2 oz. bottle is usually $3 or less.

--An eyedropper: Counting the number of drops is the easiest way to keep track of how much you're using.

--A good water source: This can be a lake, a river, a stream, etc. If you have a choice of water sources, consider these two tips:

Clear water is better than cloudy water.
Flowing water is better than still water.

Remember, though, that even if the water looks extremely pure and clean, it should still be purified before drinking. Looks can be deceiving!

Step 2: Fill Your Bottle

After finding a water source, you need to fill your bottle with water. To do this, position yourself close to the water source and tilt the bottle under the water. You want to collect water from near the surface, so don't just immerse the whole bottle in the water. Let the bottle fill up and remove it.

Examine your bottle of water to make sure there are not too many floating particles (called "floaties" in scientific terms). A couple of small floaties are fine, but too many large floaties can be dangerous. If this happens, you need to try filling up again. A way to solve this problem is to cover the mouth of the bottle with a bandanna or thin cloth that will allow water into the bottle but keep floaties out.

Step 3: Add the Iodine Tincture

Dip your eyedropper into the iodine tincture and squeeze up some of the liquid. Carefully position the eyedropper over the mouth of the bottle and add 5-10 drops per 32 fluid ounces (about 1 liter) of water. The exact number of drops is a personal choice (I can't make this decision for you) depending on the following factors:

The water source: if your source is a lake or some other still body of water, you want to add closer to 10 drops; if the source is flowing, you can add fewer.
The clarity of the water: you should add closer to 10 drops if the water is cloudy.
Your own aversion to the taste of iodine: some people hate the taste of iodine (it is a little bitter, and you will notice the taste in your purified water). If this is the case, you might want to add closer to 5 drops.

Personally, I'm a fan of 8 drops. If you are filling up a bottle or container that is not 32 fl. oz. or 1 liter, change your measurements accordingly. A 2 liter bottle will require twice the number of drops.

Step 4: Wait 5 Minutes

After adding the iodine, you need to wait 5 minutes before you can continue. You can go for a quick hike, admire nature, play a game, or think up an idea for your next Instructable.

Step 5: Thread the Bottle

After five minutes, you need to purify the mouth and rim of the bottle (which touched the original water source and which will touch your mouth). To do this, you need to "thread" the bottle. Turn the bottle upside down and slowly unscrew the top until you can see a ring of water appear around the inner rim. Once you see that ring of water, you know that the water with the iodine has touched the mouth of the bottle and disinfected it. Screw the top back on and flip the bottle right-side up.

A little water will probably leak out while threading, and that's not bad--it just ensures that you've fully threaded.

Step 6: Wait 30 Minutes, Then Enjoy!

The iodine needs time to completely purify the water. You need to wait 30 minutes before you can drink the water--plenty of time to finalize that idea for an Instructable.

After you have waited 30 minutes, your water is purified for drinking. Revel in the cool, clean taste of your iodine-infused water while you enjoy your wilderness adventure.

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243 Discussions


1 year ago

Me? I'm doing charcoal filters ONLY!! KISS

1 reply

8 months ago

I love the idea of using iodine instead of chlorine. Our diets are deficient in iodine (unless you eat a lot of seafood).

If you don't like the smell of the iodine (which most people perceive as a taste), just crush a Vitamin C tablet and add to the water, reseal the bottle, and give it a shake. The color, smell and taste will all be gone! The iodine is still in there but now it's bound to the Vitamin C and you won't notice it.

Nice Instructible!!


8 years ago on Step 6

tincture is poisonous, Lugols solution is not. Use Lugols. All of the other halogens, flourine, chlorine, and bromine are also poisonous and replace iodine (which is a necessary nutrient) in the body.

16 replies

Reply 8 years ago on Introduction

I agree. You may want to simply change Iodine Tincture Solution to 2.2% Lugol's solution. Otherwise, you may have someone who is deathly afraid of Iodine, flag your post and then keep posting over and over about how your instructable "may" kill someone or "may" cause monkeys to fly out of their butt.

Unless you have a very rare case of being allergic to Iodine, Lugol's is not only safe, but actually good for you when taken is reasonable amounts.

Using Lugol's is much healthier for you than chlorine is.

""For many years physicians used potassium iodide in doses starting at 1.5 to 3 gm and up to more than 10 GRAMS (not milligrams) a day, on and off, to treat bronchial asthma and chronic obstructive pulmonary disease with good results and surprisingly few side effects."" !!!

Please read the article yourself:

I sure am glad that the "deadly poisonous, and super duper highly toxic iodine" fear mongering is over now.

dude's before stating that something is poisonous how bout actually looking to see if it is.

Now i AM a chemist and looking up the MSDS it states the ld50 of Lugol's iodine AND tincture of iodine is 30 mg/kg! Why?? Because both Lugol's and tincture are just different ways of solubilising elemental iodine, which is poisonous but your body can hack a bit of it, same as chlorine.

Elemental iodine is very insoluble in water so it needs something to help it dissolve. Lugol's solutions uses a salt "KBr", while tincture uses ethanol and a lot less KBr, or NaBr. Your body can hack alot more ethanol than it can iodine.

This method that has been shown is technically sound, Just don't use two much iodine so you don't kill your liver.


Reply 1 year ago

It can not process industrial ethanol man!!!!!!! it will kill you


Reply 1 year ago

What do mean by "industrial ethanol"? Perhaps you are thinking of denatured alcohol? While denatured alcohol may be poisonous (depending on how it was denatured), it is very likely that the the ethanol in a tincture of iodine is NOT denatured. I say likely only because I don't know this for a fact but you can look at the ingredients on the label. If it says 5% ethanol it is not denatured. If it says 5% denatured alcohol it is. Furthermore, a few drops of 5% ethanol in a half gallon of water is totally safe, even for those who never drink.


Reply 1 year ago

I qt of cheap will kill most anything in the qt of water. More fun than iodine

Bleach also works. Prepper school:

Place the water (filtered, if necessary) in a clean container. You can use coffee filters, or towels/shirts to filter the water prior to treating it with bleach. Add the amount of bleach according to the table below. Mix thoroughly and allow the water to stand for at least 30 minutes before using (60 minutes if the water is cloudy or very cold). Treating Water with a 5-6 Percent Liquid Chlorine Bleach Solution Volume of Water Bleach Solution to Add (Clear water) Bleach Solution to Add (Cloudy, Very Cold) 1 quart/1 liter 3 drops 5 drops 1/2 gallon/2 quarts/2 liters 5 drops 10 drops 1 gallon 1/8 teaspoon 1/4 teaspoon 5 gallons 1/2 teaspoon 1 teaspoon 10 gallons 1 teaspoon 2 teaspoons Purifying water with bleach is safe if you follow the proper guidelines and use the correct type of bleach. Only use Calcium Hypochlorite bleach, and avoid using bleaches that contain perfumes, clarifiers, dyes and other additives. Be sure to read the ingredients on the label.

Copyright © Read more at:

If you have a choice between Lugol's formula and some xyz brand pushing tainted Iodine, what are you reaching for? and yes, Alcohol is POISON to the body - elementary knowledge. So what if everyone chooses it to subdue their lives - what's that old folk name they call it .. choose your poison..referring to ALCOHOL. Do you know the function of mixing Iodine with Alcohol? Again, why use inferior when you can choose the best. And the body does not 'hack' iodine, it utilizes it. You are a bit mixed up with your logic.

Alcohol is less toxic than iodine. Look up the lethal doses. Sounds like you are on a bit of an iodine mission here. Just because you take iodine every day below the level of toxicity doesn't necessarily mean it is good for you or anybody else. The body does need a very very small amount, micrograms per day, but not milligrams per day. And no, I am not a troll for the pharmaceutical industry. (That any such person would be following this tread so somewhat laughable.)


If you're replying to my post, maybe you should read it again. It's called irony.

I should have been more specific though because they're may be a few people around here who are actually dumb enough to put 10 GRAMS of Iodine in their bottle of water. You only need to use the recommended amount to purify water kids, no need to dump the entire bottle in there...

I was actually making a general statement considering all the different posts.
Potassium iodide isn't Lugol's though, just making a differentiation. Potassium iodide is used as a iodine supplement with an ld50 of 2g/kg. Not Lugols! Lugols is KBr + I2 dissolved in water and shouldn't be used as a supplement due to the free iodine, which is toxic

There is nothing toxic about lugols. Don't take my word for anything though. GOOGLE it. It would be illegal to sell lugols as an oral supplement if there was anything poisonous about it.

The same goes for vitamins. You should take one a day. They're good for you. If you try to eat the whole bottle in one sitting though, then YES, vitamins are poisonous.

So, trying to be constructive here, Lugol's has been used as an oral supplement in the past. The reason why it should not be anymore is because IT IS TOXIC. All tests on LD50 that you will find are shown for rats who have a very high tolerance, about 2 g/kg.

However they have done recent human studies and found as I mentioned before a LD50 of 30 mg/kg! Which is a heck of alot less than rats, and why they don't want people to use it, even though you are having a very diluted amount. Any lugol's MSDS within the last few years will state these values.

It is dangerous to say that something is not toxic just because you can buy it of the shelf. Warfarin (rat poison) can be bought as a blood thinner, even though it is extremely deadly. Likewise Lugols IS TOXIC, but can be used at low levels

"Lugol's has been used as an oral supplement in the past. The reason why it should not be anymore is because IT IS TOXIC."

And it STILL IS used as an oral supplement. If it were found to be "ToXiC" by any kind of REPUTABLE and CONCLUSIVE source then it would be ILLEGAL to SELL IT as an ORAL SUPPLEMENT.

"Lugols IS TOXIC, but can be used at low levels"

Everything IS TOXIC, but can be used at low levels.

And again (sighs) ANYTHING is TOXIC when used in large enough amounts.

I heard of this guy who went swimming IN PERFECTLY CLEAN WATER and he DIED of water poisoning! He drank SO MUCH of it (here it comes)... it KILLED HIM DEAD!

No more water for me! That stuff is ToXiC!

Here's some more links to different web sites ALL saying that it's perfectly FINE to use Lugol's solution to purify water.

So, what is the name of the guy who was "poisoned" by Lugol's solution? Exactly who is the "they" that you are referring to who conducted these tests? How many controlled tests did they conduct? WHO FUNDED THEIR RESEARCH? How much money is "the human" suing the company for, who tried to poison him with Lugol's solution?

And the best question of all... WHAT HAPPENED TO THAT DARNED RAT? Did he get a tummy ache? Maybe it made him turn into a pumpkin? Exactly what irreversible TOXIC reaction occurred which was so horrifying that it made "they" say:

"The reason why it should not be (used) anymore is because IT IS TOXIC."

Lugol's solution turned that poor rat into a ZOMBIE!!!

I've posted links to numerous places which ALL STATE that it is PERFECTLY SAFE TO USE LUGOL'S SOLUTION TO PURIFY WATER.


Except for the time some guy, in some lab (who probably worked for Pfizer or Bayer) PROVED that Lugol's solution is "toxic" by a test he preformed on ONE rat ...(who was also dying of terminal cancer and AIDS at the time of the test).

Steve Sextonnnnoooiiissseee

Reply 3 years ago

I am an environment, health and safety expert with experience architecting biochemical warfare agent abatement systems and other air, water and waste pollution controls for major aerospace, mining, working with industry associations and DARPA. The mixture of nascent iodine and potassium iodide comprising Lugol's Solution is not toxic to humans. It is necessary to replace the chlorine, fluorine and bromine that has keyed into every cell in your body; which, create a very toxic body condition! A therapeutic dosage of Lugol's solution is necessary for a long time (up to 1 year) to replace those halogens with iodine, which is an essential nutrient for humans. Seaweed in excess is an issue, as seaweed adsorbs metals including arsenic, of which one can receive too much. The modern medical community is now doing great work with iodine for highly deficient communities throughout North America. Do the research and get educated. All the best and respectfully,