How to Purify Water With Iodine (Complete Purification Guide)

What is the most crucial step when planning your next backcountry adventure? Ask anyone that has spent significant amounts of time outdoors, and they will all tell you the same thing—a reliable and safe method for purifying water.

Anytime you drink out of backcountry streams, lakes, or rivers, you risk becoming sick due to giardia infection. These microscopic parasites are one of the most common causes of waterborne disease and have some pretty nasty side effects such as nausea, fatigue, stomach cramps, and diarrhea.

While there are a few methods for purifying water, we will cover the advantages, disadvantages, and processes for purifying water with Iodine in the article below.

Effective Methods of Purifying Water With Iodine

When done correctly, Iodine is one of the quickest and easiest ways to purify water. In the steps below, we will cover purifying water for safe consumption adequately. 

  1. Find the best possible source of water. Ideally, you will want to find clear and running water from a stream or river. Lakes and ponds will work too but carry a higher risk with more potential microorganisms that can be harmful. You want to find the clearest water possible as it will be the most effortless water to purify.
  2. Remove anything that you can see from the water. Once you’re filled up your bottle or container, go through and remove dirt, bark, twigs, or anything else that can be seen floating around your water. A screen is an ideal removal method, but a piece of cloth such as a shirt or headband will work as well. 
  3. Use Iodine for purification. Once your water is clear of floating debris, it is time to add the Iodine. For liquid Iodine, you will add 5-10 drops to every liter of water. When using tablets, you will need to add one tablet for every liter of water. Depending on the water quality, you may need to add a few more drops or extra tablets if it is cloudy or discolored. Keep in mind that it is normal for some Iodine to have a strange taste and a hint of orange coloring. 
  4. Let it sit. The amount of time it takes for the Iodine depends on a few factors. If you are using cold water, it is recommended to mix for one hour if using drops/liquid form of Iodine and two hours for the tablet form. If you use warm or hot water, you can cut those mixing times in half.

Advantages and Disadvantages of Iodine Tablets

As with anything in life, the iodine method for purifying water is not a perfect solution. There are downsides to doing it, including severe risks to your health. Below, we will look at the good and the bad of this water purification method.

Advantages of Using Iodine

Convenience and ease of use set iodine apart from the rest of the pack. Here is a list of the most significant advantages of iodine over other methods:

  • The liquid and tablet forms take up less pack space
  • Faster purification compared to chlorine
  • Cheaper than other methods
  • It takes less effort to kill bacteria and viruses commonly found in backcountry water
  • The process is simple and effective

When you look at the benefits of iodine over some of the other water purification methods listed below, you can see the biggest advantages come down to its convenience and ease. Here are some of the other popular water purification methods:

  • Boiling water
  • Sip or Squeeze Filters
  • UV Light Purifier
  • Gravity Water Filters

Boiling water can be time-consuming as you will need to make a fire, bring the water to a boil for an extended period, and then let it cool down before you can drink it. The other methods require bulkier gear and equipment that can take up space and weigh you down. This is where iodine shines.

Stowing away some tablets in your pack or even an eyedropper and a bottle in liquid form takes up virtually no space at all. You can walk up to any river or stream, follow the process above, and have clean and safe drinking water in less than an hour.  

Iodine is also a cheaper option than the others we mentioned. A bottle of tablets has an extremely long shelf life and can cost you less than ten dollars!

Disadvantages of Using Iodine

While iodine can be a great water treatment technique for many people, it is certainly not for everyone. If any of the following pertains to you, find a different method for purification as iodine can have severe effects on your health.

  • Will require water purification for an extended length of time
  • You are pregnant or nursing
  • Have been instructed by a physician to avoid table salt
  • You have Iodine allergies
  • Experience thyroid issues
  • You have dermatitis herpetiformis

Another common complaint about iodine is that it can have an unpleasant color and taste. When iodine is dissolved into water, it has a less than appetizing look with a light orange and brown color. Iodine-treated water has been known to stain the inside of your bottles or water reservoir as well.

The taste, to be blunt, may be even worse. The taste is commonly described as slightly bitter and metallic. There are ways of improving these issues, which we will cover later in this post, but even then, it can still have a pretty bad taste to it.

One of the most significant downsides of iodine as a purification method is its inability to kill cryptosporidium oocysts found in water. Cryptosporidium is a microscopic parasite that has been known to affect humans and animals alike. Some of the side effects of the parasite and disease include dehydration, vomiting, fever, weight loss, and diarrhea.

An important fact to be aware of is that certain conditions can cause iodine to lose its effect over an extended period like moisture, humidity, and exposure to heat. Iodine also fails to remove any industrial or agricultural chemicals upstream from your water collection point.

Side Effects of Treating Water With Iodine

If you do not have any of the above conditions, iodine should be a safe approach to water purification. However, you should never consume iodine-treated water over long periods. Improper use of Iodine drops or tablets can cause some adverse side effects that include:

  • Stomach pains
  • Hypothyroidism and other thyroid disorders
  • Swollen face or lips
  • Diarrhea
  • Running and stuffy nose
  • Nausea
  • Joint pains

Having allergic reactions to shellfish is a good indicator to stay away from iodine. Watery eyes, itching, running nose, and anaphylactic shock are all symptoms of an allergic reaction. If you find yourself experiencing any of these issues, it is probably a good sign to put a stop to the iodine-treated water and use another method or consult a doctor.

How to Improve the Taste of Iodine Treated Water

As we mentioned above, Iodine water has been known to taste foul. Even with the best improvements, sometimes it is not enough to help Iodine water go down any easier. But we do have a list of some of the standard methods for making it bearable:

  • Add some flavor. It should be apparent that by mixing some sports drink powder or flavor drops can make a drastic difference in the taste. This can mask the taste and make it look better as well. It is important to note that you should never add anything to the water until the iodine has done its job with the purification. Once this process is complete, you can add your flavor and enjoy it. Drink mixes also provide the added benefit of electrolytes, which can be essential when spending hard days hiking up and down the mountains and fending off dehydration.
  • Water aerating can also make a huge difference. Aerating the water is not a complicated process. One aeration method is to shake your bottle for a short period of time firmly, let it rest for a minute, then repeat the process. You could also try getting an additional container or bottle and pouring the water back and forth between the two.
  • Neutralization tablets. When you go to a store or purchase Iodine tablets online, they will often include additional tablets for neutralization. While they may not be perfect, they are fantastic at increasing the taste quality of your Iodine water. Once you complete the process of purifying the water, just drop in your neutralizing tablet and shake it up. In theory, this should make your water taste fresh and clean like you bought it from the store.

Iodine vs. Chlorine Dioxide for Water Purification

Chlorine Dioxide and Iodine are often compared against each other as they are both tablet forms of water purification. While they are both low-cost, convenient, and practical, they do have some differences that you should be aware of before purchasing one or the other.

  • Iodine is known to absorb into the dirt and other residues that you may find in stream water, making the dosages hard to determine. When you chlorinate water, this same debris will rest at the bottom of your container, making for more transparent water.
  • Chlorine dioxide is known to be more potent and more effective than iodine at killing off parasites such as giardia and cryptosporidium.
  • Iodine can kill off bacteria, viruses, and protozoa in roughly 30 minutes. Chlorine Dioxide is more effective, but the recommended wait time is 4 hours before you can safely consume the treated water.
  • Chlorine dioxide tablets have a shorter shelf life than your standard Iodine tablets and typically expire after four or five years.

As you can see, there are a number of differences between chlorine dioxide and iodine that are important to know when choosing which approach fits your needs. When it comes to chemical treatments, both chlorine dioxide and iodine will do an excellent job if a lightweight and fast-acting approach is required.

Like iodine, you should never use chlorinated water over an extended period of time. This can have damaging effects on red blood cells, your gastrointestinal tract, and other serious health risks.

Can’t get over that harsh taste of iodine-treated water? Do other methods of water purification sound more appealing? Even as a backup plan, the convenience of iodine makes it a great “break glass in case of emergency” option to have tucked away in your gear.

Now that you are equipped with the knowledge of purifying water with iodine, you can leave the bottles at home and enjoy a lighter pack on your next adventure!