I'm going to set up a 1-gal. tank for a male betta I haven't even purchased yet. The tap water in San Diego, CA is awful and I want to use bottled water. Does anyone have recommendations or opinions? I've seen conflicting info about bottled water being a waste (just use tap water and conditioner, but that doesn't remove heavy metals), and distilled versus spring water, filtered, non-filtered, etc. I can buy store brand bottled water, Arrowhead Mountain Spring Water or Crystal Geyser (my fave to drink myself).
I plan on changing the water once a week. Is removing 20% to 25% of the water and adding new to the tank recommended, or does it have to be an entire water change? I will have gravel, a fake material plant and ornament too.