Try to see if it's still within range by testing your R/O water.
If it reads anywhere <3, you might not need to calibrate it right away.
Eventually, you will need to calibrate in the future, so go ahead and order some calibrating solution.
If it reads anywhere <3, you might not need to calibrate it right away.
Eventually, you will need to calibrate in the future, so go ahead and order some calibrating solution.