Some folk are very fussy about their water, mine comes from a 130 foot well in northern Indiana. It is hard and a bit rusty; which must be the way we like it because everybody's well is the same no matter how deep. :):)
I try to sanitize my TT tank when I fill up for the spring. We keep about 20 gallons of water in our fresh tank for those occasions when we camp and the camp water is nasty tasting or we pick a campgrounds like our State Parks which are usually electricity only.
We dump what is left in the tank when we return and refill before the next trip. We never had an issue but then I still drink from the garden hose, like I did when I was a kid.
If you are one of those folks who is sensitive to the water they drink, they do make numerous filter to help with that.
Safe Travels