Problem with bottled water is that you never know about the quality? For all we know the bottled water might be from tap water.
I used to buy the large bottles & they are very heavy. Imagine having to carry at least 7 bottles a week. Don't forget that you need water for cooking.
The plastic bottles also have chemicals that can seep into the water. Can read about the problem here
https://www.mindbodygreen.com/0-11193/7-reasons-to-never-drink-bottled-water-again.html
In Thailand some of the hotels provide glass bottles of water & the water tastes much nicer than water provided in plastic bottles. You can find glass bottled water in the stores but they are expensive & heavy.