Bluelab - PH Pen pythium we understand the importance of

we understand the importance of maintaining balanced elemental bioavailability during the flowering phase

from California's Emerald Harvest

Growth can slow down to a crawl and you'll see clear signs of deficiencies

based on NPK values

Bluelab - PH Pen pythium we understand the importance ofA compact and robust user friendly handheld pen which takes measurements in increments of 0. 1 pH and is fully temperature compensated to ensure accurate readings every time. Fully waterproof rather than merely water resistant, the Bluelab pH Pen is designed to float if dropped into a reservoir. Temperature display in C or F selectable. Hold function keeps the pH reading on screen for as long as required. Easy to calibrate, and calibration check mark