Apex ph reading 11.9 in CA reactor

[NVfishman]

Anyone know what is happening my apex shot up in a day to 11.9 and now reading 9.36. I don't know if the apex is broken? or if it is just the prob but the movement is all over the place really fast. In 5 minutes it is reading 10.4 to 9.2

[kenargo]

It sounds like either a probe or that you have something electrical within the water that is leaking current. The probe is easier to replace as a test and you don't really need to calibrate it for a test.