Most people don’t feel like they need to purchase all 3 calibration solutions and just get the 7.0 to reset their pH pen, but that doesn’t work.

Most people don’t feel like they need to purchase all 3 calibration solutions and just get the 7.0 to reset their pH pen, but that doesn’t work.
It is important to maintain the correct pH in the reservoir of your hydroponic system, to ensure a healthy and thriving plant.