how long will tap water stay okay to drink, if stored in water bottles? I know it sits in the supermarket for ages....so I presume ages.....? (not prepping for the end of the world but we've had our water cut off many times this year...sigh).
Tap water should stay ok indefinitely in theory if kept in clean bottles made from a good grade plastic so either empty water bottles filled up of 2 ltr drink bottles washed out properly and filled, keep it in the dark so the uv rays from the sun don't promote the growth of algae
In reality it will develop a flatness to its taste as a result of the oxygen within it separating and personally I would probably look to rotate it on a yearly basis
The other option is a Berkey which will purify pretty much any water for drinking and doesn't look out of place on a kitchen worktop for general day to day use, I posted a link to a you tube review on another water thread a while ago will see if I can find it again and repost for you
If you are storing water in bottles make sure you don't place the bottles on a concrete floor for storage. I think the concrete causes the bottles to deteriorate or something. Not too sure of the exact reason, sorry.