I just noticed somebody had created a new water-filtration tag. It was only used on two questions, both asked by the same person.
I retagged both questions with gear, health, and food-and-drink.
The first two fit perfect but the last one seemed a bit off. We have a tag for water but it's a bit too specific in its current form, tap-water.
Now water-filtration isn't a great tag name because the best ways to turn bad water into good water require other methods instead of or in addition to filtration. "Water purification" would cover those.
But for our site I don't think 'food-and-drink' + 'tap-water' + 'water-purification' is the best way to divide up the problem space now.
I think 'water-purification' would be good on outdoors.SE but too specific for one narrow part of a small range of related travel problems on travel.SE
Thus I think the best way is to change tap-water to water and specifically have it cover all clean water / drinking water related problems we face as travellers.
The one thing I can think of is people using the tag for water issues such as swimming. Do we think that's a concern? If so we could go with drinking-water or clean-water?
What do we think?