Following the KH Director and the ION Director, the German company GHL is now also launching the PO4 Director. This device automatically measures the phosphate level in the water using just one reagent. The new device will be available in 2027.
With the introduction of the KH Director, GHL had already automated the measurement of alkalinity. Not long after, calcium, magnesium, potassium, sodium, and nitrate followed, thanks to the ION Director. However, for reef aquarists who want to automatically monitor their most important water parameters, one crucial parameter was still missing: phosphate. With the announcement of the PO4 Director, automatic phosphate measurement is now within reach.
Smart Expansion
The PO4 Director is designed as a direct extension of the ION Director. By utilizing the existing infrastructure, the device remains compact and is easy to install. Although detailed technical specifications are not yet available, a great deal of information has already been released.
For example, the phosphate measurement uses a single reagent solution. No additional dosing pump is required for this, as the unused pump from the ION Director dosing unit is utilized for this purpose. The device also integrates seamlessly with the water supply: the PO4 Director uses the existing connection from the ION Director. Physical installation is simple, as the device connects directly to the ION Director’s AUX port. A fully automatic calibration then takes place with each measurement using the ION Director’s reference solutions. Finally, the expansion is universally compatible with all existing and future versions of the ION Director, requiring only a software update.
GHL investigated whether the existing sensor in the ION Director could be expanded to measure phosphate, but this proved technically unfeasible due to the accuracy requirements. In a reef aquarium, the phosphate concentration fluctuates around 0.1 ppm, which is extremely low compared to ions such as sodium (approx. 10,700 ppm) and chloride (>19,000 ppm). Since an ion-selective sensor cannot reliably measure such ratios, an alternative measurement method was chosen. By designing the device as an add-on to the ION Director, the measurement remains accurate without incurring high operating costs.
The GHL PO4 Director is scheduled to launch in the spring of 2027. The suggested retail price is not yet known.
