Folks, if you've recently upgraded or renewed your annual club membership but it's still not active, please reach out to the BOD or a moderator. The PayPal system has a slight bug which it doesn't allow it to activate the account on it's own.
Don't know, but you can always try to calibrate it. You should always store PH probe in 4 buffer. I have lab grade 4, 7, 10, 12.45 buffer, if you need to calibrate your PH probe.