Description
The Growlink LINKS Terralink+ with TrueEC™ is a research-grade TDR substrate sensor built for growers who need root-zone data they can actually trust. It measures volumetric water content (VWC), bulk EC, pore water EC, temperature, and permittivity from a single probe, using true dielectric EC measurement rather than the capacitance-based estimates found in most substrate sensors.
Why growers choose Terralink+
- TrueEC™ technology: True dielectric EC measurement, not a capacitance-based estimate, for genuinely reliable readings through aggressive drybacks and high-EC feeds.
- Full TDR accuracy: Time Domain Reflectometry gives research-grade moisture readings rather than the simplified capacitance sensing used in lower-cost substrate probes.
- Five measurements from one probe: VWC, bulk EC, pore water EC, temperature, and permittivity all from a single 3-element stainless steel waveguide.
- Growlink Copilot ready: Feeds directly into Growlink Copilot for automated, data-driven crop steering decisions.
- Built to last: 316 stainless steel waveguide construction designed for repeated insertion across multiple grow cycles.
Technical Specifications
| Measurements | VWC, Bulk EC, Pore Water EC, Temperature, Permittivity |
| Technology | True TDR (Time Domain Reflectometry) |
| VWC Range | 0–100%, ±5% FS accuracy, 0.1% resolution |
| Bulk EC Range | 0–6 dS/m (6,000 µS/cm), 1 µS/cm resolution |
| Pore Water EC | 0–55 dS/m (Hilhorst model) |
| Permittivity Range | 1–85, 0.1 resolution, ±4% FS accuracy |
| Temperature Range | -40 to +55°C, ±0.25°C (5–35°C), ±0.5°C (full range) |
| Waveguide | 3-element, 5cm, 316 stainless steel |
| Operating Temp | -30 to +55°C |
| Power | 4.2–15V DC, <10µA idle, 118mA read |
| Interface | SDI-12 V1.4 |
| Dimensions | 15cm x 3.3cm (without cable) |
| Weight | 121g (without cable) |
| Cable Length | 5m or 10m (included) |
| Construction | 316 stainless steel, epoxy, ABS plastic |
| Connector | M8 |
| Compatible With | canopyLINK, LINKS HUB |
| Substrate Types | Rockwool, coco, peat, soil |
Terralink+ vs. Standard Terralink
Already run the standard Terralink? Here's how the Plus compares:
| 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) |
| Permittivity | Not measured | 1–85, ±4% FS |
| Waveguide | Standard push-in probe | 3-element, 316 stainless steel |
| 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
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+ plugs into canopyLINK or the HUB via its M8 connector, feeding root-zone data straight into Growlink OS for monitoring and automated crop steering. 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 Substrate Sensor — VWC, EC & temperature
- 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).
