TrolMaster WCS-3 Water Content Sensor 3 | VWC Substrate Probe with M12 Splitter Set

What the TrolMaster WCS-3 Measures

This probe reports the moisture in a grow medium as volumetric water content, shown as a percentage. Three slim prongs slide into coco coir, rock wool or soil with little displacement, even in small cubes. A built-in LCD wakes when the sensor is tapped or moved and shows the live VWC reading. Data also flows to the controller, which can raise alarms and send mobile alerts when moisture passes a setpoint. Sensors connect over M12 cable and daisy-chain with the included T-splitter. Aqua-X Pro and Hydro-X Pro accept up to 50 sensors, Aqua-X Plus up to 20, Aqua-X up to 8 and Tent-X one. The probe runs on 12 V supplied by the system and draws 100 to 200 mA. It is rated for 32 to 122 °F and below 90% humidity, and carries CE, FCC and ETL marks. The set includes the sensor, an M12 T-splitter and a 4 ft M12 cable. TrolMaster backs it with a 3-year warranty.

Using a Water Content Sensor to Steer Irrigation

A water content sensor turns irrigation timing from guesswork into a number the whole team can read. Insert the prongs fully into the substrate, keeping them away from the pot wall and the drip emitter. Place sensors in blocks or pots that represent the room, not the wettest or driest corner. Watch the overnight dryback, the drop in VWC between the last and first irrigation. A larger dryback pushes plants toward generative growth, while a smaller one keeps them vegetative. Set high and low alarms so the controller flags a stuck valve or a failed pump quickly. Link the readings to Aqua-X so pump events can start or stop on moisture rather than the clock alone. Add sensors across zones as the room grows, chaining them with M12 splitters. Keep the probe clean and reseat it after each media change so readings stay comparable. Log the data across a crop to fine-tune the next run. With steady readings, irrigation decisions become repeatable from one harvest to the next.

Key Features

• VWC readings: Moisture shown as a percentage of the medium.
• Slim three-prong probe: Fits small rock wool cubes and coco pots.
• Tap-to-wake LCD: Live reading at the plant without opening the app.
• M12 daisy-chain: Up to 50 sensors on Aqua-X Pro or Hydro-X Pro.
• Alerts and crop steering: Setpoint alarms and mobile notifications.

Technical Specifications