FC is Zero.Elevated.
What is the FC?
I too have trouble distinguishing the PH in the kit and use the PH Meter to verify what I'm seeing. In my 1 week of use, I have not had to calibrate it at all, but its pretty darn easy to use. You turn it on, stick it in the water and it gives you the PH almost instantly.So, they are a little more of a pain to use?