Sorry I didn't call you. I am glad you found it in your secret hiding place!!
I am with the opinion that they are very persnickery! It is very dependant on where you put them, how clean they are, how new or old they are, etc...
I am just trying now to keep mine at a steady or level amount that doesn't dip too low or go too high. I found a scientific controller on ebay reasonable that will monitor pH and ORP with an ORP probe with it. It will be coming soon. I'm anxious to see how it will help measure and regulate it better.
Thanks again for the lend. It was valuable information to process what's next.