What is calcium hardness and why is this important? 

Calcium hardness is the amount of the naturally occurring mineral calcium in your water. I have seen ranges vary from a low of 80 to a high of 300 ppm. Low calcium hardness will cause the water to be corrosive, and high levels will cause cloudy water and scale. High pH and high calcium hardness will cause the calcium mineral to precipitate out of the water. Therefore, I would recommend keeping the calcium hardness between 100 and 200 ppm when using Nova Spa Water Conditioner.

Should I use soft water or my regular well water?

Nova Spa Water Conditioner will work with either soft or hard water. Most spa companies recommend a minimum level of calcium to prevent the water from becoming corrosive and affecting the pumps. So if your soft water is really low on calcium, you may have to add a chemical to raise calcium hardness. Calcium hardness over 200 ppm will cause other issues.