cypresstx86

just purchased the Hanna "checker" portable pH meter and have a couple of questions regarding usage and calibration. I've never used one before so I don't know how often I should be checking the pH level. The spa is not used that much and is mainly used by myself. It is currently treated with ozone, bromine tablets and non chlorine shock but thinking about going to one of those natural 60 days treatments available (not sure yet). But does anyone have any advice on how often I should be checking the pH levels? Also in regards to calibration, what kind of calibration intervals should I expect with this meter. I know this could vary based on usage so maybe compare intervals to usage? I purchased a couple of packets of 7.01, 4.01 and the storage solution and just wondering when I should calibrate this meter. any help is much appreciated. Thanks!