GHL calibration fluids come in a handy 50 mL bottle, making regular probe calibration fast and easy. All GHL measurement electrodes are made of the highest laboratory grade materials. To ensure consistent performance and accuracy, pH probes should be calibrated regularly; we recommend re-calibration every 30-60 days.  

pH probes are calibrated on a 2-point sample system. When calibrating pH probes, select solutions at the extremes of either end of measurement. For example, when reading typical saltwater aquarium pH ranges (7.9 to 8.5) select pH 7.0 and pH 9.0 solutions. For calibration of a pH probe used in a calcium reactor or other low pH environments, with typical pH below 7, select pH 4.0 and 7.0 solutions. 

What’s Included?

1x pH 4.0 Calibration Fluid, 50 mL