I am thinking about getting a 10 gallon tank and putting a betta in it with some friends. I have a 75 gallon tank in progress so I know my tap water parameters. I am most concerned about pH and hardness. My water tested at a pH of 7.8 and has a total hardness of 150. I'd like to do better than that. Would it be a good idea and feasible to just create a tank using distilled water? 10 gallons isn't too bad, we have other uses for distilled water in the house so keeping a couple gallons around the house for water changes and what not would not be a bad thing. Do I need to be worried about too soft water?