I have a vinyl pool so have read and confirmed that Hardness levels don't need to be as high as other types of pools. However, when I was getting my water tested today, they specifically said that if my hardness is too low, that the heater is at risk (of corrosion?). They said if not using heater, I could get away with lower levels, but not now (since I am using my heater). Are they wrong about the heater?
2nd thought, while our pool is vinyl, isn't the foundation behind it cement? But it's still OK to have a lower hardness level because the vinyl protects the cement? What about splashing on our dyed and stamped concrete deck? (I'm guessing the impact would be minimal) Thanks!
p.s. most recent reading my hardness had fallen from 164ppm to 157ppm - rounding error perhaps.