Im not sure what you are asking, weather you want to drink it or put it in te tank.
If you want to drink it, it is ok to drink. I myself fill my drink bottle with it before i work out at the gym. I like the taste of it, nothing, the city water taste horrible.
I also put it into the tank, mind you it is store bought purified R/O.
The problem with it is that it contains nothing to prevent harmful bacterias from growing, so if it's been sitting for a while or not refrigerated you do stand a chance of stomach problems.
You don't need flouride anymore. Other stuff we eat and our toothpastes contain enough. The flouride thing was from the old days when the only source of flouride was the water supply.