Help with ph controller....
It's time for cleaning, and I soaked the probe in the cleaning solution, then went to the 7.0 solution. Read 7.3, so I recalibrated it to 7.0. Then I went to the distilled white vinegar, and it was almost 4.0. Then, when I tried adjusting the slope, it would only go down to 3.4. Wouldn't turn any more. Is my probe bad? Or could I be doing something wrong? How often do the probes need to be replaced? I've only had this one since March.
55G Filstar XP3 - 16" Fire Eel
75G Medium Planted - Filstar XP3 Low Light - Established Feb 2006