I can help with ABV. For example, if you have 5 gallons to start and 6% ABV then you have (0.06)(5) gallons of ethanol, or 0.3 gallons. If you added a gallon of water, you would still have 0.3 gallons ethanol, but now your ABV would be (0.3)/6, which would be 5% ABV. You can do this with any...