Every daylight savings time, I rotate my stored water. I empty out my containers, refilling them with, then add 7 drops of bleach per gallon.

* Edit * I've been asked before what the best survival book is. Honestly, it is One Second After by William R. Forstchen. It's probably the best description scenario that could occur.

It is not those regurgitated line drawings that everyone copies from Euell Gibbons, or rehashed rule of 3's survival books.

You don’t. You have RO at the point of consumption. At any rate, it’s our approach, we store 150,000L in a cistern over the winter and use it through the summer. An under-the-counter domestic RO system can be had for like $200, the membranes last about a year with our usage, and are like $15 a pop. Post-RO storage tank UV block too because I like belts and braces.

Non-potable just goes through the usual barrels full of sand and biochar, and doesn’t need further treatment.

You rotate it every ~6 months:

* https://www.cdc.gov/water-emergency/about/how-to-create-and-...

The old stuff can be used to water house plants or your garden. If you have advanced warning of an event (e.g., hurricane), you can also fill up a large reserve 'just in time':

* https://thewirecutter.com/reviews/waterbob-bathtub-liner-rev...

Many houses have hot water heaters, which IMO is plenty for most people and the water naturally gets replaced through normal use.

At the condo, I just rotate pet bottles. They are quite fimr for like a month, outside of direct sunlight.

And water can be always treated to make it drinkable again.