My male betta has super severe fin rot so I'm moving him to a 1.5 gallon QT tank. My tap water is really hard (180ppm) with 1ppm ammonia in it and a ph of 7.6. Because the water quality is so bad, so I decided to use bottled water so my betta could recover.
I know that pure RO water is bad, so I bought purified water with minerals added. It has calcium carbonate, magnesium sulfate, and sodium bicarbonate added to it. Is this enough that the water is safe for fish? If it's not, how much tap water should I add per gallon of RO so that it has the appropriate amount of minerals? Also, should I add prime to the bottled water before putting it in?