do charter companies chlorox the water tanks

Just wondering.
do they put anything in the water to keep it clean?
My guess is no, and we did not drink the boats water- we used water from bottles.
do wonder if the water sits for weeks or months in the low season.

Not that I am aware of. We never drink the water from the water tanks. We get gallon jugs of bottled water and drink that.

pretty much a constant turn over of that water. Part of hurricane prep is to treat the water. Usually if the boat water is cold it doesn't taste bad, but generally it is warm and no water tastes good warm.