How do I measure substrate EC in my rockwool slab?

Soil Pro+ is calibrated for rockwool, coco, soil, and perlite. The substrate pins sit directly in the growing medium, so the readings reflect what is happening at root level.

How does irrigation steering reduce water use in a greenhouse?

Soil Pro+ shows how substrate VWC, EC, and temperature respond in real time as PAR and microclimate shift. The air sensor sits on top and the soil pins go into the substrate, so you see both the cause and the effect in one view. That is irrigation steering based on cause and effect, not a timer.

The Soil Sensor for VWC, EC and Root Zone Steering

Name: Sigrow Soil Pro+
Brand: Sigrow
Price: 880 EUR
Availability: InStock

Substrate water content, EC, microclimate and PAR in one device

The Sigrow Soil Pro+ is a wireless greenhouse substrate sensor that continuously measures substrate water content (VWC), electrical conductivity (EC), substrate temperature, air temperature, relative humidity, and PAR light — six variables in one solar-powered device. Each Soil Pro+ comes with its calibration designed for your substrate, so VWC and EC readings stay accurate from day one. Soil Pro+ feeds your climate computer the root-zone data needed to steer irrigation.

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Moisture Data Without Context is Just a Number

Don’t guess your irrigation decisions. Standard sensors only tell part of the story.

The Blind Spot

Standard sensors tell you how much water is in the slab, but not why the plant needs it.

The Disconnect

Irrigation decisions often ignore the microclimate and light levels driving transpiration.

The Risk

Over-watering leads to root rot; under-watering kills momentum.

Standard Sensor

Limited Data

Moisture only
No light data
No climate data

Soil Pro+

Complete Intelligence

Substrate (WC, EC, Temp)
Light (PAR intensity)
Microclimate (T, RH, VPD)

3 Critical Metrics. 1 Device.

Don’t guess your irrigation decisions. A standard moisture sensor only tells part of the story.

Hover over the device to explore each sensor area

Solar Drive (PAR Light)

Measure the energy driving your plant’s thirst. Monitor photosynthetically active radiation to understand plant demand.
PAR Light Intensity Daily Light Integral (DLI) Real-time Light Tracking

Microclimate Context (T, RH, VPD)

Understand the air layer right above the pot. Track temperature, relative humidity, and vapor pressure deficit.
Air Temperature Relative Humidity (RH) Vapor Pressure Deficit (VPD)

Calibrated Substrate (EC, WC, Temp)

The built-in EC sensor and moisture sensor unlock the secrets of your root zone. Precisely measure electrical conductivity, water content, and temperature — the most complete root zone sensor on the market.
Water Content (WC) Electrical Conductivity (EC) Substrate Temperature

Steer Your Crop with Confidence

Watch how substrate VWC, EC, and temperature respond in real time as PAR and microclimate shift. That is irrigation steering based on cause and effect, not a timer.

Real-Time Cause & Effect Analysis

This proves the “Cause and Effect” capability of the sensor

Real-time cause and effect analysis – light drives water demand in greenhouse substrate

Light Drives Demand

As PAR light increases, plants transpire more, pulling water from the substrate. This creates the dry-back effect.

Perfect Your Timing

Monitor the inverse relationship to optimize irrigation timing and prevent stress before it impacts yield.

Works With Your System

Seamlessly integrates with major climate computers and the Sigrow dashboard.

Priva
Hoogendoorn
Source
Ridder
Sigrow Dashboard

Wireless Connectivity

Connect via LoRa technology through the Sigrow Gateway. No cables, no hassle.

Your Data, Your Way

Export to your preferred platform or view in our intuitive Sigrow dashboard.

Built for Reliability

Substrates

Rockwool, Coco, Soil, Perlite — each unit calibrated per substrate

Power

Solar (Self-sustaining)

Connectivity

Wireless (LoRa / Sigrow Gateway)

Maintenance

Zero calibration needed

Measurement Range

WC: 0-100%
EC: 0-20 mS/cm
Temperature: -10 to 60°C
PAR: 0-2000 μmol/m²/s

Accuracy

WC: ±2%
EC: ±5%
Temperature: ±0.5°C
RH: ±3%

Data Transmission

Frequency: Every 5 min
Range: Up to 500 m
Protocol: Private LoRa
Battery life: 5+ years

What is irrigation steering and how does Soil Pro+ enable it?

Irrigation steering is the practice of timing and sizing irrigation shots based on what the substrate and crop actually need in the current hour — not on a fixed daily schedule. The inputs are: PAR light (energy driving transpiration), microclimate (VPD pulling water from leaves), substrate VWC (water available at the root), and substrate EC (salt balance).

Soil Pro+ measures all four signals in one device. The air sensor reads temperature, RH, and PAR right above the pot. The substrate pins read VWC, EC, and temperature inside the root zone. The relationship between the two — light driving demand, substrate responding — is the cause-and-effect view a climate computer needs to time the next shot. Irrigation steering with Soil Pro+ typically reduces water use 10-20% and stabilizes substrate EC within ±0.3 mS/cm of target across a full season. For complete root-zone coverage, growers pair Soil Pro+ with Sigrow DrainSense on the drain side.

How Soil Pro+ compares to other substrate sensors

Soil Pro+ is the only greenhouse substrate sensor that combines substrate VWC, substrate EC, substrate temperature, air temperature, relative humidity, and PAR light in a single solar-powered wireless device. Each unit ships with calibration designed for your specific substrate, so readings stay accurate without manual recalibration.

Content reviewed by Rutger Vreezen MSc, Plant Scientist & Customer Success Specialist at Sigrow. Rutger advises greenhouse growers on substrate and root-zone steering across 50+ countries.

Frequently Asked Questions

Volumetric water content (VWC) is the percentage of water by volume inside the substrate. It is the most direct measure of how much water is actually available to the roots — independent of substrate type or container size. Tracking VWC continuously (every 5 minutes with Soil Pro+) lets you see the full irrigation cycle: peak after a shot, overnight dry-back, transpiration response to dawn light. Growers who only measure drain or feed flow miss the dry-back curve, which is where calcium uptake and root-zone EC swings happen.

Substrate EC is the salt concentration in the root-zone solution. Soil Pro+ measures it with calibrated capacitance pins inserted directly into the slab — accuracy ±5%, range 0-20 mS/cm. Each Soil Pro+ ships calibrated for your substrate, so you do not need to recalibrate to match the slab type. For a tomato crop on rockwool, typical substrate EC sits between 3.5 and 5.5 mS/cm depending on growth stage. The continuous reading lets you spot drift before it stresses the crop.

Soil Mini is a portable spot-check sensor designed to map variation across a greenhouse — dry zones, hot spots, inconsistent irrigation. Soil Pro+ is a fixed, always-on substrate sensor that correlates root-zone moisture, EC, and temperature with the microclimate and light driving plant demand. Use Mini to find problems; use Pro+ to steer irrigation continuously.

Yes. Soil Pro+ integrates via API with Priva, Hoogendoorn, Ridder, and HortOS — the most common climate computers in commercial greenhouses. Data flows into your existing dashboard, so the climate computer can use substrate VWC, EC, and microclimate values to time irrigation shots, adjust EC dosing, or trigger alerts. No rip-and-replace required.

Irrigation steering matches each shot to what the substrate and crop actually need in the current hour — not a fixed schedule. By reading PAR light, microclimate, substrate VWC, and substrate EC together, Soil Pro+ gives the climate computer a cause-and-effect view: light drives demand, substrate responds. Growers using Soil Pro+ for irrigation steering typically cut total water use by 10-20% while keeping substrate EC stable within ±0.3 mS/cm of target across a full season.

Ready to reveal the power of your climate data?

Join leading growers who are preventing disease and optimizing yields with Soil Pro+’s substrate intelligence.

We’re here to support you.

Questions, assistance, or just want to chat – reach out!

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Sigrow greenhouse monitoring camera and sensor technology