Old Biscuit is exactly right. MexicoWander is, well, not living in the US at the very least. There is plenty of chlorine in the US water supply to keep your tanks fresh and clean. There is no reason at all not to use your fresh water holding tanks for all of your RVing needs. It's clean, it's fresh and it's the exact same water you use at home. Hopefully, you use the water in your taps at home to cook and brush your teeth.
If you have any concerns that a new plastic bottle is not clean (your holding tank), take a few minutes to do the bleach flush and use your RV and its associated tanks the way they were designed and the reason they were installed.
