What do you all do for water?

I've read that chins' water should be changed and their bottle washed daily to ward off bacteria and algea growth. I've also read that we should be using some type of reverse osmosis/bottled water for the chins. With 5, that would be a lot of waste of water to dump and fill 5 16 oz water bottles daily. It's not that the expense is so bad, but not having a built in reverse osmosis system it becomes a little more tricky to make sure their water bottles are cleaned and refilled daily. I have been washing weekly and filling with bottled water (walmart's brand).

Can you all share what you do as far as (1) how often you wash water bottles, and (2) what kind of water you use?

Thanks!