Aqua Master Tools P110 Pro 2 Combo Pen

Squinting at a dim display to catch a reading, or losing a pen in the reservoir, are two problems growers shouldn't have to deal with anymore. The Aqua Master Tools P110 Pro 2 fixes both: a black display with white characters makes readings easy to read at a glance, and an IP67 waterproof, floating housing means a drop into the tank costs nothing but a rinse.

This upgraded Combo Pen builds on the success of the Aqua Master Tools P110 Pro Combo Pen with AAA batteries in place of button cells, selectable 1 or 2 decimal precision, and a calibration reminder that triggers after 30 days so accuracy never quietly drifts. A dry storage electrode means you don't need to keep it soaking in liquid between uses, and the replaceable electrode keeps the pen serviceable for years.

Dried salts around the pH electrode are normal and not a sign of a problem. Before first use, soak the electrode in tap water for at least 12 hours to dissolve any salts and properly activate it.