I just tried calling Aquatic Eco Systems, unfortunately, they were already closed for the weekend, so I will try next week. Also, I took another reading at the pond today with the meter's altitude/elevation set to 0 (sea level) and was getting 10.1-10.2 mg/L at 60*F.

-Chris
1 acre pond
Currently managing:
FHM, GSH, GSF, BG, PS, RES, LES, YP, SMB, LMB, HSB, RBT, WE, CC, FHC, and Grass Shrimp