I currently use the four way test strips for ph, free chlorine, alkalinity, and cyanuric acid and see no water problems. When I read this site and look at other test kits though there are many more parameters, including the following which I do not test for:
total hardness
total chlorine
total dissolved solids (TDS)
copper
acid/ base demand
My questions are the following:
Are any of these parameters things I should be testing if my water seems OK?
Is having high cyanuric acid bad for me, my tub, or my ducky?
Does total chlorine just to tell you when to shock?
Does TDS just tell you when to change the water?