Focustronic Mastertronic by PASS Aquatics
Basic Specification:
| Parameter | Accuracy / Precision (+/-) |
|---|---|
| NO3 (Nitrate) | 0.5 ppm / 0.1 ppm |
| PO4 (Phosphate) | 0.01 ppm / 0.005 ppm |
| Mg (Magnesium) | 20 ppm / 20 ppm |
| Ca (Calcium) | 6 ppm / 6 ppm |
| dKH (Alkalinity) | 0.1 dKH / 0.05 dKH |
| OLI (Organic Matter) | Derived parameter indicating organic load in water |
Features:
- High precision stepper and DC pumps
- State-of-the-art colorimetric photosensor
- Simple to use via iOS and Android app (Wi-Fi)
- Connects to Alkatronic, Dosetronic, Solartronic, and Powertronic devices via local Wi-Fi through router
FAQ
Can the Focustronic Mastertronic measure organic matter in water?
Yes, it measures OLI, a derived parameter that indicates the level of organic matter in the water.
Is the device compatible with other PASS Aquatics products?
Yes, it can communicate with Alkatronic, Dosetronic, Solartronic, and Powertronic devices via local Wi-Fi through a router.
What is the accuracy of phosphate measurement?
The phosphate (PO4) measurement has an accuracy of ±0.01 ppm and precision of ±0.005 ppm.


Adam Slater –
The Focustronic Mastertronic has been a game changer for my aquarium. The phosphate and nitrate readings are extremely accurate, which helps me maintain a stable environment. The app is easy to use and provides real-time data. I can now monitor all key parameters from my phone without needing to manually test the water.
Jasmine Walker –
I’ve used this device for two months now and it’s reliable. The magnesium and calcium readings are consistent, and the OLI feature helps me catch organic buildup early. The only minor issue is that the app occasionally needs a restart to sync with the device.
Benjamin Pullman –
The precision in measuring phosphate is impressive. I used to struggle with algae growth, but now I can adjust dosing based on real-time data. The integration with other PASS devices makes it a seamless part of my aquarium system.