I don't use the fluoride cartridges because I get my drinking water from my brothers well. I use city water for everything else. But I would probably use them if I had to drink the city water.

But then again, I would probably just build a couple of solar stills. I have the supplies on hand to make a few of these.

Larry was making a couple on the side on days off and I sold them while he was on the road. They actually work pretty good. One, on a good sunny day, can purify enough to meet the drinking needs of several people for a day.