Description
Neptune Apex A3 Jr Aquarium Controller
What’s Included
- A3 Apex Jr Base Unit
- Temperature Probe
- pH Probe
- Magnetic Optical Sensor (MOS)
- LD-2 Leak Detection Sensor
- Multi-plug Power Supply
Essential Monitoring Now, Expandability Later
- Temperature, pH, water level, and leak detection monitoring
- Instant notifications when issues occur
- User-friendly Apex Fusion interface
- Two Aquabus ports for expansion
- Remote access from anywhere
Most aquarists spend a significant portion of their day away from their aquariums, making real-time monitoring essential. The Neptune Apex A3 Jr tracks critical parameters such as temperature, pH, water level, and leaks. If any parameter moves outside acceptable ranges, you will receive immediate alerts through the Apex Fusion cloud interface.
This allows you to detect and respond to issues such as CO2 overdosing, heater malfunctions, or leaks before they escalate into serious problems.
A3 Apex Jr Base Unit
The base unit serves as the central controller, connecting all probes and sensors while linking your system to the Apex Fusion interface. It includes power input, two Aquabus ports for expansion, a temperature probe port, a pH probe port, and two FMM ports for sensor integration.
Magnetic Optical Sensor (MOS)
The MOS is designed for accurate water level monitoring. It can be placed just below the water surface to detect drops in water level and trigger alerts or automated responses.
This sensor can be mounted on aquariums or reservoirs with wall thickness up to 1/4".
LD-2 Leak Detection Sensor
The LD-2 sensor is designed for use on flat surfaces such as inside cabinets, on floors, or near filtration equipment. If water comes into contact with the sensor, the system will immediately send an alert so corrective action can be taken.
Lab Grade, Double Junction Probes
The system includes high-quality temperature and pH probes for reliable monitoring. Calibration is simple through the Apex Fusion interface, and the double junction pH probe provides stable readings with reduced calibration frequency.
For aquarists seeking a reliable entry into aquarium automation with the ability to expand over time, the Neptune Apex A3 Jr offers a practical and scalable solution.

