Oh shit I didn't see that the hydro shop DID a cal for you. That is really freaking weird. I'd take it back and find out what they did, and have them re-check it against their buffers. What is the brand of meter?
stinkyattic Reviewed by stinkyattic on . hydro store messed up ph calibration HELP STINKY hey i was in my hydro store today saw the calibrating meter i asked did they do mine they told me to bring it in the said it was off so they calibrated now all it reads is very high like 11.4-16.0 ph dumped alot of ph down no change scared to feed my plants the open tomorrow at noon what to do just wait? Rating: 5