Water Purification Tablets – Why You Should Have Some


There are several methods for emergency disinfection of drinking water. Each with their own attributes and effectiveness.

One method to treat water for drinking is to use water purification tablets.


Water Purification Tablets – Advantages


1. Small and lightweight

A typical small bottle (50 tablets) of the most popular brand (Potable Aqua) will treat 25 quarts of water.

Potable Aqua Tablets for treating water

Potable Aqua Water Purification Tablets

(comes with ‘neutralizing’ tablets to help offset the iodine taste)

It’s easy to do and takes up very little space in a pack compared to a portable filter. I’m not degrading the usefulness of a good portable water filter! Instead I’m pointing out another alternative.

Note that boiling water will ensure safe drinking (except for any potential chemical contamination).

Continue reading: How Long to Boil Water for Safe Drinking


2. Fast

It’s fairly time efficient. The tablets listed above will treat water in about 30 minutes.


3. No fuel required

No need to use fuels for boiling water.


4. No problem in cold weather

In cold temperatures filter membranes and mechanisms can rupture or break without your knowledge. Potable Aqua tablets are unaffected by freeze thaw.


About Potable Aqua Tablets

Water purification tablets

Each tablet contains 20 mg of Tetraglycine Hydroperiodide, which “liberates 8 mg of titratable iodine when released into water.”

One iodine tablet will treat 2 cups of water while two tablets will treat one quart.

Though there’s no expiration date, the manufacturer says once the bottle of tablets is opened, it’s best to replace them for “next season”.

Further information, “as a general rule tablets that are grayish/brown in color are good and tablets that are yellowish/green should be replaced.”

The tablets are not intended for long terms use.


How To Use

1) Drop 2 tablets into 1 quart or liter of water, cap loosely and wait 5 minutes.

2) Shake container to sanitize screw threads, then tighten cap.

3) Wait 30 minutes.

4) Add two PA Plus Tablets (neutralize taste) and shake well.

3) Wait 3 minutes, then drink!

Water purification tablets are effective against Giardia lamblia when used as directed.

The following tablets are also effective on Cryptosporidium, though 4 hours is required for full effectiveness:

Potable Aqua Chlorine Dioxide Water Purification Tablets

They’re convenient to have when camping and traveling or when you’re on the move and don’t always have the time to make a fire, boil water, then wait for it to cool before drinking. A nice addition to one’s emergency kit.

Tip: These tablets go hand in hand with having a canteen.

Caution: For those allergic to shellfish, or IV (contrast) dye, or allergic to iodine, don’t use this product. Though you likely already know this.

Continue reading: Stainless Steel Canteen – Single Walled for Boiling Water

More: iOSAT ™ Tablets For Your Nuclear Survival Kit


  1. – Ken –
    I have long added these to every vehicle first-aid kit. If it comes to walking out, I would definitely scavenge these along with the first-aid kits. I have used them in the past, mostly for Canadian River water in the Texas Panhandle. That water had a lot of biological contaminants. Nowadays, I would be more concerned about heavy metals in that particular river.

    They are lightweight and easy to pack/carry. When you cannot boil your water for whatever reason, they are easy and quick to use. The older ones did not have the taste improving tablets with them. We used to use grape kool-aid. Probably why I can’t stand the stuff today. LOLOL
    – Papa S.

    1. Yes, they’re just another alternative. It’s good to have options…

      Normally I would filter or even boil. However there are scenarios where this wouldn’t be a recommended option. Tabs are easy, small, and effective as described.

    2. (I have used them in the past, mostly for Canadian River water in the Texas Panhandle.)

      Canada Texas are like 1,000 miles apart. I don’t understand how you are drinking potentially bad water from Canada while that far away?

      1. – Chuck- Just check a map of Texas, the Canadian River is located in the Texas Panhandle. It’s a bit like how many rivers are named the “Red River”.
        – Papa S.

  2. Thanks for the article, Ken. I have one bottle of tablets but I rather tend to go in heavier on filters. Filters can have issues in cold weather and are not cheap. But tablets are not effective against chryptospridium. And, given the quantity of water treated by each method, filters are probably more cost-effective and take up less space.

    1. Burt G, I have updated the article with alternative tabs that will work on crypto – although a longer waiting period for full effectiveness (4 hours).

  3. They don’t work on crypto.
    Too big a chance to rely on just these

      1. Huh that’s interesting. I’m glad they’ve fixed it. They used to even teach in classes that they didn’t. Good deal

  4. 4/30/2013 Katadyn water purification tablets, 50 count, $20.31 free shipping. Vendor? Katadyn
    2/18/2019 50 count, $40.63 free shipping PLUS $3.25 tax. Vendor? Katadyn
    Just looked these up. No inflation?

  5. We had decided a long time ago to avoid not to carry pills of any kind. My concern is the extreme temperatures that occur in a car could/might render the pills ineffective.

  6. I have several boxes of tablets called Aqua Cure, 30 tablets to a box. Each box treats 8 gal. water. It says the tablets are intended for clarification and disinfection of polluted or suspended water. Suspended?? I guess that means junk in the water. Anyway, it’s suppose to be safe to drink in 15 min., and you can strain it if it’s to junkey. The active ingredient is Sodium dichloro-s-triazinetrione. Is this stuff going to mummify me? Or should I just get some of those Potable Aqua tabs.? It says recommended for use by the military during field exercises, but I don’t know about regular use.

  7. Ken;
    Thank you for the article on the purification tablets. I have not really considered stocking them….

    Sorry also that 90% of the comments are on the SFFA but we do get lost sometimes.

    Please know I and many others appreciate these article’s……

    NRP aka Grumpy OLD Fart

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