GroStar | GS1 PH/Temp (2-IN-1) Pen

The GS1 is a pocket pH and temperature pen for checking nutrient solution and runoff. It has automatic temperature compensation, a large backlit screen that changes color, and an IP67 waterproof rating.

The double-junction probe is replaceable, so when it wears out you swap the probe instead of buying a new pen. It runs on AAA batteries and turns itself off when idle.

What's included: pH 7 and pH 4 calibration solution (50 ml each), 10 ml KCl storage solution, lanyard and manual.

Warranty is 2 years on the instrument and 1 year on the Swiss-made probe.

Tip: keep a few drops of storage solution in the cap between uses. A probe that dries out gives slow, drifting readings.

Pairs with: GroStar pH Calibration Kit pH 4/7/10, GroStar GS1-E replacement pH electrode, General Hydroponics pH Up and pH Down.