Yup- the main problems are, that I've hear of or seen:
-Too delicate for growroom conditions
-Long stabilization time
-Inability to read low ionic strength solutions accurately- this is the most important.

Remind me to post a pH electrode maintenance sticky one of these days, lol... There are ways to slap a slow electrode back into shape.
stinkyattic Reviewed by stinkyattic on . Anyone have instructions for Hannah Ph meter? So i took my newly purchased, used digital ph/ppm meter up to the local hydro shop so i could get it calibrated. Well the guy didn't know shit about hannah meters and after messing with it for a bit, he gave up. I did buy 7.0, 4.0 and ppm calibration solution. My question is: Why does it say while calibrating ph, "use 6.86"? it use to say use 7.01. then it goes to use 4.01. So I do all of that, using 7.0 where it says 6.86. Still reads funny. maybe i need a new electrode? Any info on the Rating: 5