DIY Water Purification With Iodine
If you have spent any time whatsoever studying emergency preparedness, you are no doubt aware that water originating from an unknown (or sketchy) source can be made safe to drink by adding everyday household bleach. This is, basically, exactly what municipal water providers are doing when they chlorinate drinking water. You just have to get the dosage correct. Unfortunately, different sources will give you different recommendations, but I would say that you would be safe using as few as 16 or as many as 20 drops per gallon of water. If the water is brackish or discolored in any way, then you need to filter it through a plain white T-shirt or some other cloth that is free of dyes prior to treating it, then shake it vigorously to mix and aerate the liquid and let it sit for between 30 to 60 minutes before drinking it. That's pretty much all you have to do, but it is also important that you are not using any of the fancy scented bleaches or a brand with any kind of dyes in it, and you might consider boiling it before you do anything else, just to add an extra layer of safety. That is pretty much water purification using bleach in a nutshell.
What some folks might not know, however, is that you can also purify water using iodine. In fact, one of the leading brands of water purification tablets marketed for campers, hikers, and other outdoor enthusiasts Potable Aqua contains iodine as an active ingredient.This method apparently works best when the water is right about room temperature. Best if you give it to around 68-70°F. To be honest, I'm not sure why this matters, but pretty much every source I was able to locate agrees on this point. An important point to remember is that anyone with thyroid problems, those taking lithium, pregnant women, and even any woman over 50 years of age should consult a physician before ingesting iodine. That is the typical disclaimer, but YMMV so your choices are up to you alone.
The first step, as with the bleach method, should always be straining the water through a clear piece of cloth like a plain white T-shirt. If the water is clear, you don't necessarily have to do this, but it only takes a few moments and gives you an added layer of protection. Plus, water with particles floating in it always has to make you wonder a bit. That may simply be in your (my) head, but who needs the extra stress of worrying about something you can easily fix in an already stressful situation?
Then, add the tablet(s) to the water. Typically, I stir the water somewhat to facilitate the tablets dissolving. Again, it may just be in my head, but it seems to me like being completely dissolved is the only way to be sure the water has received the proper dosage of the purifying chemical(s). After the tablets have completely dissolved and are no longer visible, wait about 30 minutes for them to do their job murdering the bacteria before you drink the water.These are only basic guidelines. You will want to follow the directions listed on the label of the bottle the tablets came in to be sure. Also, normally you will find yourself using one tablet per every quart or liter of water you are attempting to purify, but again the instructions that go with the specific product are the guidelines you should use.
It should be noted that some people dislike the slightly bitter taste the iodine causes the water to have, so it is a good idea to carry a few powdered drink packets that you can simply pour into the bottle (or whatever container you are utilizing) and shake it up. There are also prepackaged tablets available for sale that remove the iodine taste and any kind of smell from treated water.
Treating water with iodine can also be achieved without prepackaged tablets through the use of a tincture solution of iodine, which usually contains 2% pure iodine and 47% alcohol (source). Using these materials, you're going to want to add between five and 10 drops of the tincture per liter of water. The cloudier the water is, the more likely I would add the full 10 drops, and you will need to manually adjust these numbers based on the size of container you are personally using at the time. Again, as with the tablets, wait 30 minutes before drinking and use your powdered drink mix if the taste of the iodine is too much for you.