I run tap water though one of these:
It is a four stage filter, is bacteriostatic, lasts for 4,000 gallons, requires no special housing or adapters, and costs ten bucks at Walmart. It makes great tasting water and ice.
When I packed a lunch all day in the Arizona sun, I re-used about a dozen bottled water bottles. I would fill them up 90% with filtered tap water and freeze them. They kept my lunch cold and provided me with cold water all day (I carried an medium size igloo cooler.)