How often to test calcium hardness?

[MillerCourtResort]

My fill water has a calcium and hardness level of 247 ppm, and I have a vinyl liner. How often should I test the calcium hardness? I have an automatic cover, so almost no rain and very little evaporation. I normally refill a little only after backwashing.

 

[Newdude]

If it's stable you can test CH or CYA monthly. Adjust frequency as needed.

 

[MillerCourtResort]

Is purplish ok or do I keep dripping until I see blue blue?

 

[dBsooner]

Keep drops going until the solution no longer changes color. You'll subtract the last drop that didn't change the color from your count.

 

[duraleigh]

+1 what dBsooner said