This post may contain affiliate links.

Potable Aqua Iodine Water Purification Tablets Review

Potable Aqua Iodine Tablets Water Purification Review

Potable Aqua Iodine Water Purification Tablets remain a popular method of backcountry and international water purification in developing countries, despite the increased availability of alternate purification methods like chlorine-dioxide tablets.

Iodine Water Purification – Pros and Cons

Using iodine tablets is not for the faint-hearted because they turn clear water a nasty-looking brown that tastes mildly astringent to drink. Iodine stains the inside of drinking bottles and reservoirs, and your clothes if you spill it on them. While it’s effective in killing viruses and bacteria, iodine tablets are only moderately effective in killing giardia lamblia, according to the CDC, despite the manufacturer’s claims to the contrary. It’s also ineffective against cryptosporidium.  The CDC also advises against consuming iodinated water for more than a few weeks. Pregnant women, those with a history of thyroid disease, and those allergic to iodine should not drink iodinated water. Iodine tablets have also been banned from sale in European countries because of these health reasons since 2009.

In defense of iodine tablets, they can make a good addition to emergency preparedness kits (in addition to a filter to remove protozoa and other hard-shelled parasites) because they not expire when stored properly and they help limit the intake of radioactive material in the event of nuclear war. Iodine tablets are fast acting (30 minutes per liter), lightweight and about half as expensive as chlorine dioxide tablets, like Katadyn Micropur.

Potable Aqua Iodine tablets (left) will turn your water a nasty brown and give it an astringent taste. PA+ Plus Tablets remove most (but not all) of the color and offensive taste.
Potable Aqua Iodine tablets (left) will turn your water a nasty brown and give it an astringent taste. PA+ Plus Tablets (right) remove most (but not all) of the color and offensive taste.

You can also neutralize the brownish color and remove some of the Iodine taste by adding vitamin C to water that’s been treated with Potable Aqua Iodine Tablets, using PA+ Plus Taste Neutralizer Tablets, tiny tablets which are usually sold with the iodine tablets to make them more palatable. You add these *after* the iodine tablets have purified your water, otherwise they’ll interfere with the purification process. The PA+ Plus tablets take 5 additional minutes to work. If they haven’t completely dissolved in that time, you can still consume the water.

Bacteriological Effectiveness: Giardia Lamblia?

Why does Potable Aqua claim on the product label that their iodine tablets kill Giardia when the US CDC (Center for Disease Control and Prevention), states that iodine tablets only have a low to moderate effectiveness in killing Giardia? (see A Guide to Drinking Water Treatment and Sanitation for Backcountry & Travel Use)

So I called up Potable Aqua’s customer service number and asked them specifically about the CDC report. They told me that “if Giardia is a primary concern, we recommend that people use Chlorine Dioxide tablets instead of Iodine Tablets. They are also available under the Potable Aqua Label.”

Comparable Chemical Water Purification Products

ProductActive IngredientVirusesBacteriaGiardiaCryptosporidium
Potable Aqua Iodine TabletsIodineYesYesNoNo
Potable Aqua Iodine and PA+ Plus TabletsIodineYesYesNoNo
Polar Pure Iodine CrystalsIodineYesYesNoNo
Potable Aqua CIO2 TabletsChlorine DioxideYesYesYesYes
Katdyn Micropur TabletsChlorine DioxideYesYesYesYes
Aquamira CIO2 LiquidChlorine DioxideYesYesYesYes


If you need to protect yourself from giardia, a protozoa found in commonly backcountry water sources, and prefer using a chemical purification method over a filter or UV light, don’t use Potable Aqua Iodine Tablets. They are not effective against giardia or cryptosporidium, another hard shell parasite, which is an increasing concern in backcountry water sources. Iodine water purification tablets are really only effective against viruses and bacteria, and more appropriate as a second stage purification method to kill viruses after removing giardia and cryptosporidium with a water filter. Even then, using Potable Aqua’s Chlorine Dioxide Water Purification Tablets is preferable over iodine tablets, because they don’t turn your water brown, have a less offensive taste, and don’t have potentially harmful health effects.

The author purchased this product.

SectionHiker is reader-supported. We only make money if you purchase a product through our affiliate links. Help us continue to test and write unsponsored and independent gear reviews, beginner FAQs, and free hiking guides.


  1. Back in the ’70s and even into the ’80s, that was all my brother and I could find in the stores we shopped. My brother was the one who told me the purifier was vitamin C. If I didn’t have the neutralizer tabs, some Tang would do the trick… and make the water taste better too.

    • I went the filter route myself. But I did drink Tang and eat Space Sticks when I was a kid and we had a space program.

      • Back in the ‘80s, when we hiked in wilderness areas of Montana, my brother would tease me because I treated my water while he drank straight from the source. He used water right out of the stream for several years, but after a bout with giardia, became a believer in water purification.

        We used to also mix Tang with instant tea, cinnamon, and some other spices and called it “Whang Tang”. I miss that stuff… but probably don’t miss all the sugar and empty calories.

  2. I tried using iodine tabs for water disinfection in the 1980s. After a month I started breaking out in horrible itchy lesions (lichen planus), deep ones that left permanent scars. After a lot of medical runaround and testing, they finally decided it was an iodine allergy. It left me so sensitive that to this day I cannot eat seafood or iodized salt or multi-vitamins containing iodine. It wreaked havoc with my social life–I can’t accept dinner invitations. I’ve also found that many restaurants use iodized salt, which limits me to green salads when eating out. I strongly urge folks to use something other (and more effective) than iodine!

  3. Langleybackcountry

    I honestly do not understand why iodine is even sold as a viable option any more. There are so many other cost-effective, more reliable, less fussy (the waiting, water temps, etc.), and lower risk options. If you can spend a couple hundred on a tent, you can spend a little making sure your water is safer. Or carry more fuel and boil.

  4. Completely agree with your assessment. The only things keeping PA iodine useful are both listed above:
    – it comes with the nifty little PA+ ascorbic acid/vitamin C tablets that you can use on chlorinated water too. Each one should remove the chlorine taste from about 2 quarts. Then you can throw away the iodine pills.
    – it can go in your weird prepper kit since it never expires (assuming it doesn’t change color) and protects you a bit from radioactive fallout.

    There is more risk in Europe because lots of areas – mostly in the east – were never covered by ancient seas and there is no appreciable iodine in the soil or foods that grow in it. As a result there are more people with thyroid goiters. These goiter swellings eagerly take any iodine they find and make it into thyroid hormone, which can lead to a severe thyrotoxicity. This is less common in other places. Under other circumstances iodine can suppress the thyroid, which is why it’s not safe for pregnant people- the baby might come out without the benefit of thyroid hormone and be severely disabled. Again, I agree that there are better options.

Leave a Reply

Your email address will not be published. Required fields are marked *

Captcha loading...