Summary #

The KH Director is an automated measurement and control system designed to monitor and stabilize Alkalinity (KH) in saltwater aquaria. By utilizing a lab-grade pH sensor and a precise titration process, it provides highly accurate data and enables the automated regulation of KH without the need for manual testing.

Applies to #

• KH Director

Overview #

The KH Director uses an automated acid-base titration method to measure Alkalinity. This allows for real-time monitoring and precise control of KH dosing schedules or calcium reactors, ensuring that your water chemistry remains stable. The KH Director provides high-precision data specifically for Alkalinity (KH / dKH).

Note: For comprehensive monitoring of your water parameters, the KH Director can be perfectly combined with the ION Director, which monitors Calcium, Magnesium, Potassium, Sodium, and Nitrate.

How it works #

The KH Director automates the traditional titration process to eliminate user error and subjective interpretations, such as guessing color changes in manual drip-test kits. To ensure lab-grade precision, it manages the entire testing cycle independently:

• Objective Measurement: Instead of relying on visual color changes, the KH Director uses a lab-grade pH electrode to pinpoint the exact endpoint of the acid-base titration.
• Fully Automated Testing: The system automatically draws the required water sample, accurately dispenses the KH Reagent, and calculates the exact KH value based on the specific volume of reagent used.
• Safe Disposal: After the test is complete, all fluids are pumped out into a separate waste container. No reagent or test water is ever returned to the aquarium.

System Requirements #

The KH Director operates as part of the GHL ecosystem and requires specific hardware to manage the measurement logic and fluid movement.

• Required Controller: You need a GHL device with PAB-Master capabilities, such as a ProfiLux 3, ProfiLux 4, or a GHL Doser Standalone.
  Note: GHL offers various Starter-Sets that already include a Doser and the KH Director.
• Required Dosing Pumps: Three dedicated pump heads on a GHL Doser are necessary (Sample water, KH Reagent, and Waste water).
  Important: Only standard GHL Dosers can be used. The KH Director is not compatible with GHL Doser Maxi pumps for the titration process.
• Included Components: The KH Director is shipped with a lab-grade pH sensor, KH Reagent, calibration fluids, and the required tubing.
• Communication: All devices are linked via the ProfiLux Aquatic Bus (PAB) system for secure, interference-free data exchange.

Core Use Cases #

Automated Monitoring & Alarming

The KH Director replaces the need for subjective manual testing by performing measurements at user-defined intervals (e.g., from once a day up to multiple times a day). If values deviate from your desired setpoint, the system can trigger alarms or send push notifications via the GHL Connect app.

Dynamic Dosing Control

The system can actively stabilize your water chemistry by adjusting your liquid KH buffer dosing schedule in real-time. It offers two primary modes to control connected dosing pumps:

• Add-on Mode: The KH Director calculates the deficiency and adds an extra dose on top of your existing schedule to return the value to the setpoint.
• Adaptive Mode: The system automatically scales your entire dosing schedule (e.g., your Balling or Triton base doses) up or down by a percentage to match the current consumption of your reef.

Calcium Reactor or Kalkwasser Control

Instead of adjusting liquid dosing pumps, the KH Director can control a Calcium Reactor or Kalkwasser stirrer. It can automatically adjust the reactor’s output by switching the CO2 solenoid valve or regulating a variable speed feed pump based on the current KH reading, ensuring a perfectly stable Alkalinity level.

Data Logging & Trend Analysis

All measurement data is logged and can be viewed in the GHL Control Center or via GHL Connect. This allows you to track how your aquarium reacts to changes in livestock, salt brands, or lighting over long periods.