....we don't, because sterilizing the fresh water tank every trip out is a real PIA. If our tank was sterilized every time out, along with the replacement water, I would drink from the tank. We buy a known brand of safe bottled drinking water locally before heading out (10 or 15 gallons in dispensing bottle), and use it exclusively for drinking or washing salad/fruit or making cold juices. If we have to buy an unknown brand of drinking water on the road, we stick to well-known national brands that have a lot to lose if it ever got out that their water was contaminated...
Also, remember if you have an air pocket in your fresh water tank (probably the case with every RV fresh water tank), that air in said pocket is full of bacteria, mold spores, and what not; so you'd need to make that stored water kill these things on its own during storage.
...end//
