The Solution pH Pen from Bluelab is a compact, professional-grade tool designed for fast, accurate pH and temperature measurement in hydroponic systems, soil, coco, and nutrient solutions. Just like the brand’s other products, including the Soil pH Pen and 3-in-1 OnePen, the pH Pen from Bluelab is fully waterproof, while the floatable body and bright backlit LCD make it reliable and easy to use in any environment. The durable double-junction probe delivers consistent precision, while automatic temperature compensation (ATC) ensures dependable readings in changing conditions. With a low-battery indicator, auto-off feature for extended battery life, and pocket-sized design, the Bluelab pH Pen is built for daily use and trusted by growers worldwide.