I’ve been using spring water because San Diego has terrible hard water and ammonia. I’ve tried everything to cut the ammonia down but spring water was the answer. I still have the problems with hard water and I don’t know how to solve it. Spring water still shows the water hard. Do I have to resort to R/O water and where can you get this? Or any other suggestions?

For a ten gallon tank you should be okay doing a partial 20-25% water volume change per week as regular maintenance. To be sure, you would monitor the water parameters with water test strips to find out levels of ammonia, etc. There are more advanced “smart” monitors that I do not currently have experience with, but a basic aquarium thermometer will also tell you the water temp. A 5-gallon would be plenty for 1 betta, but a 10-gallon is not too big so long as you create a natural habitat environment with plants (real or fake) and decorations, substrate, etc.

Good point. I updated that section and agree with you but it was for unfiltered tanks.. keep up on the partial water changes and all is well unless for deeper cleanings due to other circumstances.