The Bluelab pH Pen is the most ergonomic and easy to use pH pen available for hydroponics and indoor gardening. The Bluelab pH Pen is completely waterproof, so you don't have to worry about accidentally dropping it in your solution. The Bluelab pH Pen also has one button push calibration. No more hard to follow instructions to make sure your pH meter is accurate. Storage and calibration solution is required for maintenance and longevity of your pH pen.
 
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