This is a new one for me so I could use a little guidance here. I recently drained and filled our spa and have been trying to get the water in balance but I'm getting unusual ph readings from my test kits. The oto tests are reading around 8.0-8.2, yet I'm getting readings of around 7.2-7.5 on my test strips. I've used three different test strips and 2 different oto tests, one is from my tf 100 kit. All tests were performed within 5 min window, and all test materials used aged from 1 yr to a few months old. My normal inclination would be to trust the oto kit but based on my experience owning the spa for the last 6 years, the test strips would be more in line with what I would expect it to be. Other readings are as follows:
Bromine - 5-7ppm (just shocked yesterday)
Ta - 60
Ch - 150
Ph - ??
Any ideas on what the heck is going on?