The only downside to this product is the 4 hour wait time. I got around this on a recent trek up Kilimanjaro and 2-1/2 weeks in Tanzania by buying iodine tablets that took a half hour (plus 30 min. additional if using the neutralizing tablets) and then using these overnight to purify the water in my Nalgenes. There is little aftertaste and it helped me conserve the iodine which I needed during the day. You will also need a knife or scissors to open these, so if you're camping make sure you bring a Swiss Army knife or something. Overall, a good product I will be using again on multi-day trips and visits to developing countries.

Really pleased with these in that there is less fear of a breaking hard plastic or glass bottle. As long as I carry these in a protected spot in my pack so the package doesn't get too smashed, I'm confident in this product. Just make sure you read the directions first. These will take 4 hours to work, so plan ahead of your water running out or prior to meals--and try to mark your drinking containers ahead of time with the amount that will match the formula liquid measurements best. This seems like a superior choice to even other choices in the "Potable Aqua" line, as far as what it is supposed to taste like afterwards as well.

Just remember, chemicals won't be eliminated, and you should probably always use a coffee filter or bandana, etc to filter out any debris from standing water sources prior to putting in the tablets...if you are desperate and can't find CLEAR water from a stream or river to purify instead.

For several years I have been drinking reverse osmosis filtered water only, at home and at work. I carry two or three liters of it to work with me every day for that purpose. My tap water is lightly chlorinated and not fluoridated. The untreated tap water tastes good, and the RO filtered water tastes great. I got these tablets for use on trips but decided to test them first with RO filtered water to find out how they affect water taste and see if I have any adverse reaction to drinking it.
My Results
Tablets received on time and not even close to expiration date. Tablets are easy to use as directed and dissolve with fizzing action like Alka Seltzer in about four minutes. I followed directions and used one tablet per liter of RO water, using both glass bottles and stainless steel bottles. While tablets are dissolving a stream of bubbles rise from it and creates a mild distinctly chlorine odor. In the clear glass bottles used I could see the water was clear and white and colorless before treatment and clear and very slightly yellow/brown after treatment. Ten minutes after treatment the treated water tastes like highly chlorinated tap water. I have tasted worse in numerous municipalities here in USA. 36 hours later the taste is unchanged, highly chlorinated. In the past 36 hours I have drunk three of the four liters I treated and have had no noticeable physical consequences. The stainless steel bottles were not corroded or stained by the tablets.

These tabs are very small and light and I look forward to carrying them with me on my next trip and being protected from pathogens in the water.

Like the Chlorine Dioxide over the Iodine based purification tablets.

First I filter with my Sawyer, then drop a tablet my 1 liter polycarbonate water bottle, let it work, then shake vigorously to aerate the water.

Have a lot of confidence that this is the safest way to deal with Beaver Fever and viral waterborne critters.

Care enough in my BOB/GHB to make at least 10 liters.

Haven't decided if I'd use these in a stainless steel bottle - not sure if there's some risk of interaction with the metal.

Package was smashed flat but tablets were not crushed. Individually foil wrapped to keep tablets from oxidizing. Expiration date was good: 04/26.