Description
The Growlink Terralink provides reliable substrate monitoring — volumetric water content (VWC), electrical conductivity (EC), and temperature — direct from the root zone. Built with TDR (Time Domain Reflectometry) technology, Terralink gives growers a dependable read on what's actually happening in the substrate, cycle after cycle.
Why growers choose Terralink
- Accurate root zone monitoring: Measures VWC, EC, and temperature with dependable precision across most substrate types.
- Reliable in demanding conditions: Consistent performance through both high-EC feeds and aggressive dryback cycles.
- Growlink Copilot ready: Feeds substrate data straight into Growlink Copilot for automated crop steering.
- Easy installation: Push-in design with an M8 connector — no exposed wiring to thread through the canopy.
- Wide substrate compatibility: Works across most soil and soilless media (avoid mixes containing perlite or clay pebbles).
Technical Specifications
| Technology | Time-Domain Reflectometry (TDR) |
| VWC Range | 0–100%, ±3% accuracy |
| Bulk EC Range | 0–18,000 µS/cm, 1 µS/cm resolution |
| Temperature Range | -40 to +55°C, ±0.25°C accuracy |
| Dimensions | 7.25" x 2.25" x 1.75" |
| Cable | 2m, M8 connector, included |
| Compatible With | canopyLINK, LINKS HUB |
Need longer reach? Extend your Terralink cable with the M8 extension 5m cable.
Terralink vs. Terralink+
Want research-grade True EC and pore water EC on top of your VWC and temperature readings? Here's how the standard Terralink compares to Terralink+ with TrueEC™:
| Spec | Terralink | Terralink+ |
|---|---|---|
| EC Technology | Standard TDR | TrueEC™ (true dielectric) |
| Measurements | VWC, EC, Temperature | VWC, Bulk EC, Pore Water EC, Temperature, Permittivity |
| VWC Accuracy | ±3% | ±5% FS, 0.1% resolution |
| Bulk EC Range | 0–18,000 µS/cm | 0–6 dS/m (6,000 µS/cm) |
| Pore Water EC | Not available | 0–55 dS/m (Hilhorst model) |
| Cable | 2m, M8 connector | 5m or 10m, M8 connector |
| Best for | General substrate monitoring | Research-grade crop steering and multi-room precision setups |
Not sure what to buy first? Start with a kit.
Choose a starter kit based on what you want to automate first — every kit works together and expands over time.
Irrigation Starter Kit
For growers who want automated irrigation with root-zone visibility and climate monitoring.
- canopyLINK Sensor HUB — £299
- valveLINK Controller — £399
- Terralink Substrate Sensor x2 — £598
- Climalink Climate Sensor — £399
Bundle price: £1,376.95
Monitoring Starter Kit
For growers who want real-time climate and root-zone visibility before adding automation.
- canopyLINK Sensor HUB — £299
- Terralink Substrate Sensor — £299
- Climalink Climate Sensor — £399
Bundle price: £1,056.00
Using it with a Growlink PIC? The PIC has no M8 socket. Cut the M8 plug off and wire the sensor into the PIC terminals, or for more reach plug it into the 5m M8 extension and cut the plug off the far end of that instead. Full wiring steps are on the PIC page. The PIC is being replaced by canopyLINK + valveLINK, which take this sensor plug-and-play.
Part of the Growlink LINKS Ecosystem
LINKS is Growlink's modular grow-room hardware system: small, purpose-built devices that each do one job well, and click together into a whole-facility control network. Terralink handles substrate monitoring — VWC, EC, and temperature — plugging into canopyLINK or the HUB via its M8 connector to feed root-zone data straight into Growlink OS. Every LINKS device can run wirelessly on its own over Wi-Fi, but connecting to the HUB over a wired RJ-45 connection unlocks whole-room automation, longer signal range, and the ability for the HUB to power and enable additional LINKS hardware across the facility.
Explore the rest of the LINKS range
- canopyLINK Sensor HUB — connects up to 8 climate & substrate sensors
- valveLINK 8-Channel Irrigation Valve Controller — automated, sensor-triggered irrigation
- ClimaLINK Climate Sensor — aspirated temp, RH, VPD & light
- Terralink+ with TrueEC™ — research-grade TDR substrate sensing
- batch tankLINK — automated nutrient tank monitoring
- nutriLINK — 8-output precision nutrient delivery
- HUB 8-Port Communication Controller — wires the whole system together
- Digital lightLINK — dimming & spectrum control
- 4 Channel lightLINK — fan speed, dimming, 0–10V
Powered by Growlink OS
"Run cultivation from a system that learns."
Every Terralink connects into Growlink OS, the cultivation management portal that turns your best irrigation practices into living Blueprints — standardised schedules and automation logic you can roll out across every room. Growlink OS includes Nova, Growlink's built-in AI, which compares performance across rooms, flags deviations from plan, and answers questions about crop performance without you having to dig through spreadsheets.
Want the full methodology behind zone-based irrigation scheduling? Download Growlink's Precision Irrigation Playbook V21 (PDF).
