Well lets see.......Nov. 18th, 2006 I filled our fresh water tank
As of today it still has water in it.
When it gets down to 1/3 tank I fill it back up.
The one time I did drain it was after we had to fill with well water source.
Other than that........it's never been drained just topped off as needed.
The tank is nothing more than a very large water bottle.
The water is treated, tested and is deemed safe from the various agencies across the USA.
Course I grew up on a ranch and drank from horse troughs, muddy pools and green water hoses....ate dirt and bugs too :B