I don't know what's going on and please stop saying stuff like that. I absolutely love both mine, and you're scaring me now. These are supposed to be some of the best in the industry. I use a generic 4 and 7 without a problem. I'm pretty sure any calibration solutions would be fine, as long as they are somewhat new. I always try to grab mine from the back of the shelf, since that's probably where the newest stuff is.

I sure hope it's nothing serious and you get it fixed soon. I think you and I bought ours basically about the same day. I'm sorry I can't be of more help, but I would try reading the troubleshooting part of the instructions again, then visiting their web site Bluelab : Manufacturers of the World's favorite pH, EC, CF and ppm handheld meters and controllers, or contacting the guy who you bought it from or bluelab tech support or customer service.

Bummer man, real sorry. The only thing different I can think of is I don't store my probe in acid. That never really made sense to me, even though several manufactures recommend doing so. Doesn't acid dissolve stuff? I always rinse mine thoroughly and store it with tap water in the sponge. My tap water is 7.6.
Opie Yutts Reviewed by Opie Yutts on . Rhizome/Opie/Anyone who uses Truncheon PH Meter Help!!! I can't get mine to calibrate lately! I've tried cleaning the probe, and even changing the contact ring (only had it about a month....:() but I keep getting that flashing green 5. It calibrates to the 4.0 solution I have (made by BlueLab) but not the 7 (made by Hanna) although it DID calibrate to the hanna solution previousyly. Any tips? I use new solution each time and check it once a week, keep the cap with 4.0 solution damp on the sponge and rinse the probe each time I use it. HELP!! Rating: 5