Please post a full set of test results. We can not advise you based on one number.
There is no such thing as a magic CH number. Scaling of calcium or etching of plaster results from a combination of factors. You can only be properly advised if you post all of your test results.
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006