OK,  lets get some information up,

Its recommended that you leave your pH probe immersed and running for at least 48 hours before attempting calibration.

For use in a calcium reactor, use pH4 solution and pH7, float the unopened pouches in your tank for a few minutes so they are the same temp as the tank/reactor you are monitoring.

For marine tank measuring, use pH7 and pH10 solutions.

I have found it best to clean the probe monthly(use AQ cleaning solution) rinse with tank water, in my opinion its best NOT to use R/O water.  For ultimate accuracy calibrate at the same time, however for most applications every other month is OK.

Ian

I am trying to calibrate my ph probes but there is a message that says that the calibration has not been possible.

What is wrong?