good morning everyone, I have a problem with my kh director, after three months of perfect functioning, he began to measure a kh between 12 and 13, verified with traditional tests the real kh is 8, so I performed probe calibration, emptying cell, but still not working properly, at this point I set a 25% reduction and began to release more precise data. but it doesn't seem normal to me. how can I do ?
Tanks
Max