With the KH Director, GHL automated the measurement of alkalinity. With the ION Director, calcium, magnesium, potassium, sodium and nitrate followed. For reef keepers who want their most important water values measured automatically, one value was still missing: phosphate. Automatic phosphate measurement is now within reach.
We are addressing this value with the PO4 Director.
The PO4 Director is an extension to the ION Director. It uses the ION Director’s infrastructure, which keeps the device compact and the installation simple. We are not going into technical details yet, but here is what we can already say:
PO4 Director
The last missing value: phosphate.
Key facts
One reagent
Phosphate measurement with only one reagent.
Extension to the ION Director
Connected to the AUX port of the ION Director.
Automatic calibration
Fully automatic calibration with every measurement, using the ION Director’s reference liquids.
All ION Director versions
Compatible with all ION Director versions on the market and those to come; only a software update is required.
No additional doser
The pump of the ION Director’s doser that is still free is used for the reagent.
Shared sample line
The ION Director’s sample line is shared.
Why a separate device?
Some may ask whether the ION Director’s sensor could simply have been extended to phosphate. We considered this, but it fails on the achievable accuracy.
At around 0.1 ppm, the phosphate concentration in a reef aquarium is tiny compared to the other ions the ION Director measures. Sodium is at about 10,700 ppm, chloride even above 19,000 ppm. A ratio of this magnitude cannot be measured reliably with an ion-selective sensor.
GHL therefore investigated other methods and, with the concept of an add-on to the ION Director, found a way to measure phosphate reliably, accurately and simply, at low operating cost.










