Hanna GroLine Hydroponic Nutrients Monitor HI981420 | pH, EC, TDS & Temp

Around-the-clock readings from the Hanna GroLine hydroponic nutrients monitor

The HI981420 is a wall-mounted monitor that sits beside the reservoir and reads three parameters continuously from one probe. That probe is the HI1285-8: a pH electrode with a renewable cloth junction, an amperometric EC/TDS sensor and an internal temperature sensor. All three sit in one polypropylene body on a 2 m cable. Ranges run 0.00 to 14.00 pH, 0.00 to 10.00 mS/cm, and 0 to 5000 ppm on the 0.5 conversion factor. Accuracy holds at ±0.05 pH and ±0.1 mS/cm across the lower half of the conductivity scale, where most recirculating feeds live. Temperature covers 32.0 to 140.0 °F and compensates every reading, so a cold reservoir in the morning does not read as a weak feed. The enclosure is rated IP65. Nutrient mist and splash reach everything eventually, and a sealed face keeps a meter on the wall instead of in a drawer.

Hydroponic nutrient monitoring that catches drift between hand checks

Probe placement decides whether the number on the screen matches the tank. Submerse the probe tip at least an inch and a half into moving solution. A return-line outlet or the draw side of a pump reads true; a dead corner of the tank lags by hours. Logging runs on its own every fifteen minutes and holds the last thirty days, keeping minimum, maximum and average values for each parameter. That history is where a pattern shows up instead of a surprise. You see the pH climb that starts two days after a res change, or the conductivity creep that only appears during lights-out. High and low alarms flash the display and trip an LED when a parameter leaves the band you set for it. One Quick Cal sachet calibrates pH and conductivity together, which is the practical difference between recalibrating on schedule and putting it off. This unit monitors and does not dose; it reports what the solution is doing and leaves the correction to you. The probe supplied with it is the unthreaded submersion type, so plumbing a sensor into a line calls for the threaded inline model instead. Keep the protective cap on the pH bulb whenever the probe is out of solution for more than a few minutes. A dried-out bulb is the commonest way one of these ends up reading slow.

Key Features

• 3-in-1 HI1285-8 probe: A pH electrode, an amperometric EC/TDS sensor and an internal temperature sensor share one body, so one port covers continuous pH and EC monitoring.
• Quick Cal single-solution calibration: One HI50036 sachet calibrates pH and conductivity together, which cuts the weekly routine down to a couple of minutes.
• 30-day automatic datalog: Records every 15 minutes and stores minimum, maximum and average values for each parameter.
• High and low alarms: A flashing display and an LED mark the moment a parameter leaves the range you set.
• IP65-rated enclosure: Sealed against the mist and splash that come with a working nutrient room.
• Selectable TDS factor: Switch between 0.5 and 0.7 so the ppm figure on screen matches the scale your feed chart uses.
• USB-C data transfer: Pull the log straight onto a memory stick or a PC without proprietary software.
• Ambient light sensor: Dims the green-backlit LCD so a bright readout is not fighting a dark-period room.

Technical Specifications