Calcium calibration solution or calibration standard is needed to calibrate meters for extra precision. 
This calcium 2000 ppm calibration solution will last up to 300 calibrations of LAQUAtwin meters. Equivalent solution of HORIBA calibration solution Y051H.
We recommend calibrating your LAQUAtwin meters daily (if you measure daily) or after every 10 measurements within a single day if you are testing more intensively.

⚫ Standard solution concentration: 2000 ppm (2000 mg/L) of Calcium (Ca2+)
⚫ Great for calibrating Calcium ion meters
⚫ Compatible with HORIBA LAQUAtwin Ca-11 and B-751 
⚫ Equivalent solution of HORIBA calibration solution Y051H
⚫ Volume: 60 ml bottle with a twist top cap
⚫ Made in USA