can my fresh water go stale?

I didn't read all the posts, yet, but change it out. A lot of campgrounds have very low pressure and sediment and nasties in their water. We use it from the tank, at good pressure and refill the tank through a good filter(s).
If it sits more than a few days we add some drinking water chlorine/freshner, from CW or Wally World and others. The water they put in the tank, more than likely has some chlorine in it, often a lot. I would dump it anyway and ill with filtered good water and add some chlorine if it is not going to e used in a few days.

tinner12002 wrote:
We always drain fresh tank after use. Never drink from tank either always carry cooking and drinking water separate...just the way we do it. I would never leave water in tank when not using the RV...its not like its expensive to refill the tank when needed.

Exactly, I dump when home and refill when taking a trip. The weight helps the ride so I fil it up. If I was worried about mileage, I wouldn't have a RV.
I have a reverse osmosis filter at home with a tap sink side for drinking water and making coffee. My wife still buys bottled water, I can't convince her the water out of the RO tap is the same stuff.

Draining the tank only does so much good. At least for my tank several quarts of water are left behind. I would have to tilt the RV to get more out and even then the water left behind and the moist environment would grow bacteria and mold.

I have no problem drinking water from the RV tank. Mine is properly sanitized at the start of use and periodically if not used. I drink water from the tank. It is just as reliable as water from any water fountain or other supply. I do use a Britta filter in the RV and at home I have a whole house filter, which probably does little, and a final charcoal filter. Even those are overkill.

Many people seem to drink nothing but bottled water. Sadly the quality of bottled water is often worse than simple household tap water. There is typically less regulation and less testing of bottled water. Much of it is just filter tap water. Storage does not help the purity.

We always drain fresh tank after use. Never drink from tank either always carry cooking and drinking water separate...just the way we do it. I would never leave water in tank when not using the RV...its not like its expensive to refill the tank when needed.

Two week and a pitri dish in the FW tank, only if not clean to start with!
The water will get "Stale" after a couple months if nor at least partly used and refreshed with clean water.
Using only clean water is the secret.

Ther are no fresh water it is all recycled and often stored for years.
Frank.

It also depends on how good of water you are putting in the tank. I bought a used TT once where they had been using bad well water to fill the tank. . The fresh water tank had crud stuck to the insides of it. After just a week of leaving water in there it would get stinky and green. After a couple of years of using clean water the tank it was in much better shape and the water in it would last longer before getting all funky.

We don't drink water from the TT tank, but I sanitize it now and then to prevent bad odors. And I drain it after every trip.

wnjj wrote:
Maybe I'm just lucky.

That's the understatement of the month, maybe the year.

If....your fill water has a high chlorine content, that might be the reason.

If it does NOT (well or other untreated source) then that is like playing Russian Roulette with 5 bullets and only one empty slot.

When we have our trailer at our seasonal campsite, I leave water in the fresh tank for about two months at a time as back-up for the toilet. Every now and then something will go wrong in the campground and they will need to shut the water off for a couple hours, so having tank water is handy.

Last year someone pulled out with a motorhome without disconnecting and yanked part of the plumbing out of the ground, so you never know.

I would not use it for drinking though.