Calcium Hardness Test Using The Palintest Pooltest 9

[woodsage]

I've been using this unit for testing my pool water and I have a question regarding the calcium hardness test. I have a plaster SWG pool. When testing for calcium hardness and waiting the recommended two minutes before testing, I get initial readings in 280 ppm CaCO3 range. If if then continue to push the "read" button, the reading will creep upwards 10 ppm each time I press the "read" button so that after many "read" pushes I will get a reading of 500 ppm over a 5 minute time period. My question is, is the very first reading I get the "real" number for testing purposes or is it an average over a 5 minute period or is it the last reading...? Also, should I be reading this test as ppm of CaCO3 or as ppm of CA? This is the only test in my series of tests that has this upwards creep of test results.

Thanx,

Rick

 

[chem geek]

You should probably contact Palintest about this problem. My hunch is that the first reading, after waiting the recommended time before doing a reading, is the correct one. You could also compare the result against a known good test kit such as the Taylor K-2006 or the TF-100. As for units of measurement, Calcium Hardness (CH) is measured as ppm CaCO₃ as is Total Alkalnity (TA).