TrolMaster WCS-9 Substrate Sensor 3-in-1 (VWC, EC & Temperature)

Anyone who's worked with substrate sensors knows that a single sensor lies to you. Not because it's poorly calibrated — because it measures one point, and substrate is never uniform. The plant on the right side of the slab is sitting at 65% VWC and the one on the left is at 48%. One is overwatered, the other is drying out, and your sensor is giving you a single number that represents neither.

The TrolMaster WCS-9 is built to solve exactly that problem. Its multi-node architecture lets you connect up to 4 sensor nodes to a single display, placed at different points across the substrate. The display calculates and shows the true average across all four — VWC, EC and temperature — eliminating the distortions caused by hot spots, water channeling, and salt buildup zones that mislead single-point sensors.

That reliable average is what makes TrolMaster's Feed on Demand strategy viable: irrigation triggered by actual moisture data, not by timer. You define the dry-back target and the system fires irrigation automatically when the substrate hits that value — with short shots, precise dry-backs, and independent schedules for morning, noon, and evening. Real crop steering, without the manual math or constantly adjusting timers.

During Feed on Demand events, the reading frequency increases automatically: from one data point per minute in normal mode to one every 10 seconds during irrigation. You see substrate behavior in real time during the shot — when it absorbs, when it runs off, when it equilibrates.

Compatible with the full TrolMaster controller family, though scalability varies significantly between models. The flagship Aqua-X Pro (NFS-2) and Hydro-X Pro (HCS-2) support up to 50 WCS-9 displays at full capacity — 200 nodes total — built for large installations with multiple independent rooms. The Aqua-X Plus (NFS-3) scales up to 20 displays. The more compact models — entry-level Aqua-X (NFS-1), Tent-X (TCS-1) and Green-X (GCS-1) — support a single display with its 4 nodes.

Scaling capacity by controller:

▸ Aqua-X (NFS-1): 1 display / 4 nodes

▸ Aqua-X Pro (NFS-2): up to 50 displays / 200 nodes

▸ Aqua-X Plus (NFS-3): up to 20 displays / 80 nodes

▸ Hydro-X Pro (HCS-2): up to 50 displays / 200 nodes

▸ Tent-X (TCS-1): 1 display / 4 nodes

▸ Green-X (GCS-1): 1 display / 4 nodes

Calibration is straightforward: factory pre-calibrated for rockwool, and for other substrates you only need to calibrate the 100% VWC point in saturated medium. No need to touch the rest of the curve.

Access to the TM+ Pro app is free, no subscription: unlimited historical graphs, configurable high/low alarm thresholds, and push notifications to your phone. No monthly fee model — increasingly rare in this segment.

What's in the box:

▸ 1 × WCS-9 Sensor Display

▸ 1 × WN-9 Sensor Node

▸ 1 × 16ft RJ12 Cable Set (≈ 4.9 m)

▸ 1 × T-Splitter

Main features:

▸ 3-in-1 sensor: VWC, EC and temperature in a single device

▸ Multi-node architecture — up to 4 nodes per display with automatically averaged readings

▸ Compatible with traditional and high-bulk EC soilless substrates (coco, rockwool, peat moss)

▸ Dynamic reading: 1 data point per minute normally, 1 every 10 seconds during Feed on Demand

▸ Enables automatic irrigation driven by actual moisture — not timers

▸ Built for crop steering: multiple set points (morning, noon, evening)

▸ Factory pre-calibrated for rockwool — only 100% VWC calibration needed for other substrates

▸ Free TM+ Pro app: unlimited history, alarms, mobile push notifications

▸ Scales up to 50 displays / 200 nodes on Aqua-X Pro and Hydro-X Pro

Technical specifications:

▸ Model: WCS-9

▸ Input voltage: 12V — 0.1A

▸ Max input current: 0.1A

▸ Water content range: 0-100%

▸ EC range: 0-30 mS/cm

▸ Temperature range: 0-50°C

▸ Operating temperature: 0-50°C

▸ Operating humidity: ≤90% RH

▸ Compatibility: NFS-1, NFS-2, NFS-3, HCS-2, TCS-1, GCS-1

▸ Weight: 0.63 kg

▸ Package dimensions: 138 × 170 × 64 mm