Hanna GroLine Nutrient Dosing System with Inline Kit HI981413-10

The Hanna GroLine Nutrient Dosing System HI981413-10 is an automated EC, TDS, and temperature controller designed to maintain consistent fertilizer concentrations in hydroponic reservoirs, greenhouse irrigation systems, and other recirculating nutrient applications. Its integrated peristaltic pump automatically doses concentrated nutrient solution according to the grower’s selected conductivity set point.

This HI981413-10 configuration includes the HI30033 EC/TDS and temperature probe plus the components needed for an inline installation. The controller supports proportional or on/off dosing, adjustable alarms, automatic temperature compensation, and protective functions intended to reduce nutrient overshooting and pump operation under unsafe conditions.

Key Benefits

• Automated nutrient management: Continuously monitors conductivity and doses fertilizer according to the programmed EC or TDS set point.
• Integrated peristaltic pump: Eliminates the need to purchase and wire a separate nutrient dosing pump.
• EC, TDS, and temperature monitoring: Tracks three important nutrient-solution measurements through one HI30033 probe.
• Proportional dosing control: Slows dosing as the measured concentration approaches the target, helping reduce set-point overshooting.
• On/off control option: Provides straightforward dosing for applications where proportional control is unnecessary.
• Inline installation kit: Includes the fittings, injector, filter, and tubing required for integration into a recirculating irrigation line.
• Color-coded display: Uses green, yellow, and red backlighting to make operating and alarm conditions easy to identify.
• Configurable safeguards: Startup delay, maximum dosing time, high and low alarms, and optional level or flow-switch input help protect the system.
• Grow-room-ready enclosure: The IP65-rated enclosure resists dust and water jets when correctly installed.
• Wall-mountable design: Keeps the controller visible and accessible without occupying reservoir or workbench space.

Measurement and Control Specifications

• EC Range: 0.00–10.00 mS/cm
• EC Resolution: 0.01 mS/cm
• EC Accuracy: ±0.10 mS/cm from 0.00–5.00 mS/cm and ±0.20 mS/cm from 5.00–10.00 mS/cm
• TDS Range: Up to 9,900 ppm, depending on the selected conversion factor
• TDS Resolution: 1 ppm
• TDS Accuracy: ±2% of full scale
• TDS Conversion Factor: Adjustable from 0.45–0.99
• System Temperature Range: 23–140°F, or -5–60°C, when used with the included HI30033 probe
• Temperature Resolution: 0.1°F or 0.1°C
• Temperature Accuracy: ±0.9°F or ±0.5°C
• Temperature Compensation: Automatic, with an adjustable coefficient from 0.0–2.4% per °C
• Pump Flow Rate: Adjustable from 0.5–3.5 liters per hour, or approximately 0.13–0.92 gallons per hour
• Maximum Pump Pressure: 14 psi
• Control Modes: Proportional or on/off
• Power Supply: 100–240 VAC, 50/60 Hz
• Enclosure Rating: IP65

HI30033 EC/TDS and Temperature Probe

The included HI30033 combines conductivity and temperature measurement in one probe designed for fertilizer solutions:

• Measures EC, TDS, and temperature
• Stainless steel conductivity sensor
• Chemical-resistant PVDF body
• Integrated temperature sensor
• Automatic temperature compensation
• Quick Connect DIN connection
• Approximately 6.6-foot cable
• 1/2-inch NPT thread for inline installation
• 3/4-inch NPT thread for continuous reservoir immersion
• Maximum pressure of approximately 43.5 psi at 77°F

Install the probe where nutrient solution is well mixed and moving steadily. Avoid locations where air bubbles can collect around the sensor, since trapped air may cause unstable or inaccurate conductivity readings.

How Automated Nutrient Dosing Works

The HI981413-10 continuously measures the nutrient solution and compares its conductivity with the programmed set point. When used to add fertilizer, the controller activates its pump when EC or TDS falls below the target.

In proportional mode, the pump automatically slows as the solution approaches the set point. This helps prevent excessive fertilizer from being injected faster than the reservoir can circulate and stabilize.

The controller can add nutrient concentrate, but it cannot remove dissolved fertilizer. If EC rises above the desired level, the reservoir must normally be diluted with suitable source water or otherwise corrected by the grower.

Inline Installation Guidelines

The HI981413-10 is intended for integration into a recirculating nutrient or irrigation line:

1. Mount the controller vertically where it is protected from direct sunlight, continuous dripping, and excessive vibration.
2. Install the HI30033 probe in the supplied inline fitting or saddle.
3. Position the probe in an area with consistent solution flow and minimal air bubbles.
4. Install the nutrient injection point downstream and sufficiently separated from the probe.
5. Connect the aspiration tubing between the nutrient concentrate container and the pump inlet.
6. Connect the dispensing tubing between the pump outlet and injection valve.
7. Prime the pump before enabling automatic control.
8. Confirm that circulation is operating before beginning nutrient dosing.
9. Calibrate the probe and program the desired set point, control mode, alarms, and dosing limits.

Separating the probe from the injection point gives concentrated fertilizer time to mix into the solution before another measurement is taken. Poor mixing or installing the injector too close to the probe may produce unstable readings or repeated dosing cycles.

Electrical connections and permanent installation should be completed by appropriately qualified personnel. Disconnect power before servicing or wiring the system.

Calibration

The controller supports automatic one-point conductivity calibration using either:

• 1.41 mS/cm conductivity standard
• 5.00 mS/cm conductivity standard

TDS readings are derived from the EC measurement and the selected conversion factor. Calibrating conductivity also calibrates the corresponding TDS display.

For reliable performance:

1. Inspect and clean the probe before calibration.
2. Pour fresh conductivity standard into a clean container.
3. Place the probe in the standard while avoiding trapped air bubbles.
4. Allow the reading to stabilize.
5. Complete the calibration through the controller menu.
6. Discard the used standard rather than returning it to its original container.

Calibration frequency depends on operating conditions, but the probe should be checked regularly and whenever readings appear inconsistent.

Alarms and Dosing Protection

The HI981413 includes several configurable functions that support dependable automated operation:

• High and low EC/TDS alarms: Alert the grower when conductivity remains outside the selected range.
• Maximum dosing-time protection: Stops the pump when it operates longer than the programmed limit.
• Startup delay: Allows circulation and readings to stabilize before automatic dosing begins.
• External level or flow-switch input: Can prevent dosing when reservoir level or solution flow is inadequate when used with a compatible sensor.
• Alarm relay: Provides a connection for compatible external warning equipment.
• Manual pump control: Allows the pump and tubing to be primed during setup or maintenance.
• Color-coded backlight: Provides visual indication of normal operation, attention conditions, and alarms.

Optional flow switches, level sensors, external alarm devices, and separate pH controllers are sold separately unless specifically stated otherwise.

What Is Included

The HI981413-10 inline configuration includes:

• GroLine EC/TDS nutrient dosing controller
• Integrated peristaltic dosing pump
• HI30033 EC/TDS and temperature probe
• Inline mounting saddles and fittings
• Nutrient injection valve
• Aspiration filter
• Flexible aspiration tubing
• Rigid dispensing tubing
• Conductivity calibration standard
• Calibration beaker
• Power connection cable
• Quality documentation and instruction manual

Package contents can be revised by the manufacturer. Consult the current product packaging or documentation to confirm included accessories.

Routine Maintenance

• Inspect the probe regularly for fertilizer residue or mineral buildup.
• Clean the probe with a compatible Hanna cleaning solution when necessary.
• Calibrate after cleaning and before critical growing cycles.
• Check aspiration and dispensing tubing for cracking, blockage, or leaks.
• Inspect the injection valve and aspiration filter for accumulated fertilizer salts.
• Replace worn peristaltic pump tubing according to operating conditions.
• Confirm that the pump is correctly primed before returning to automatic control.
• Test alarms and maximum dosing-time protection periodically.
• Keep the controller enclosure clean and ensure cable connections remain secure.

Important Usage Notes

• The HI981413-10 controls nutrient concentration through EC or TDS measurements; it does not measure or adjust pH.
• Automated pH control requires a separate system such as the Hanna GroLine HI981412 pH Dosing System.
• Never allow concentrated fertilizer to be injected without active solution circulation.
• Begin with conservative dosing settings and verify the reservoir response before increasing pump speed.
• Choose the appropriate TDS conversion factor for the feeding chart or conductivity scale being used.
• Avoid installing the probe immediately beside the nutrient injection point.
• An IP65 rating does not make the controller submersible.
  • Follow the current Hanna Instruments manual for installation, calibration, electrical connections, and maintenance.