A3 Apex Unboxing and Mounting

This guide is all about getting familiar with the hardware that comes with the Neptune Systems A3 Apex and learning how everything connects together. We’ll walk through what’s included in the box, identify the ports on each device, and show where probes, sensors, and cables plug in so you can confidently get everything mounted and connected.

 

What’s Included

 
 
A3 Apex Base Unit Main brain for monitoring, automation, and alerts
 
Energy Bar 832 Smart power control with per-outlet monitoring
 
LD-2 Leak Detection Sensor Optical leak detection for flat surfaces
 
Magnetic Optical Sensor (MOS) Low-profile optical sensor for water-level alerts
 
Temperature Probe Tracks temperature trends and equipment control
 
pH Probe Double-junction probe for reliable pH readings
Also Included
6′ AquaBus Cable
pH Calibration Solutions (7 & 10)
Mounting Screws
Getting Started Card
 

Identifying the Ports on the A3 Apex Base Unit

 

Use the labeled image below to get familiar with the ports on the A3 Apex Base Unit. Note that the 12V port in the upper left is unused. This port accepts a 12V power supply, which can keep the base unit up and running during power outages when it, and your internet modem/router, are plugged into a battery backup system.

A3 Apex Base Unit ports labeled diagram

Aquabus Ports (2)

Ports for connecting Apex modules. This is also the port used to establish a connection with the energy bar, which will provide power to the base unit.

FMM Ports (3)

Connections for Neptune Systems fluid monitoring sensors such as the LD-2 Leak Detector and Magnetic Optical Sensor (MOS) included with this kit.

Temperature Port

A dedicated port for the included temperature probe, which allows the Apex to continuously monitor aquarium temperature and trigger alert or automations.

pH Port

A dedicated port for the included double-junction pH probe, which allows continuous pH monitoring.

Switch Inputs (6)

A versitile connection most commonly used to connect a breakout box (sold separately), which can support switches and sensors for advanced automation.

Ethernet Port

This port can be used instead of WiFi for a more stable and reliable network connection.

 

Identifying the Ports on the Energy Bar 832

 

The Energy Bar 832 includes multiple power outlets and expansion ports. Use the labeled images below to identify each connection point.

Energy Bar 832 front view showing 120V outlets
Energy Bar 832 side view showing control and expansion ports

8× 120V Outlets

These outlets provide individually controlled AC power for common aquarium equipment like heaters, return pumps, lights, and skimmers. Each outlet can be turned on or off automatically based on schedules, sensor readings, or custom Apex programming, and power usage can be monitored per outlet.

3× 1Link Ports

1Link ports provide both power and data over a single cable for compatible Neptune Systems devices. These ports eliminate the need for a separate power supply while allowing the Apex to directly control and monitor supported equipment such as the DOS QuietDrive or Trident Testers.

2× DC24 Ports

DC24 ports supply low-voltage power for Neptune accessories that don't require standard AC outlets. These ports are typically used for items like small utility pumps, solenoids, or fans and can be controlled through Apex programming.

3× Aquabus Ports

Aquabus ports are used to connect Apex modules and accessories to the system. They allow devices to communicate with the Apex base unit while also providing power to supported modules, making it easy to expand the system as your setup grows.

Note: These are NOT USB ports. Do not plug USB devices into an AquaBus port.

 

Mounting the Apex

 

Mounting the Apex system is straightforward, but placement matters. Choose a dry, well-ventilated location with easy access for probes, power cables, and future expansion. Purpose-built control boards can help keep everything organized and safely away from water.

Mounting the A3 Apex base unit

Mounting the Apex Base Unit

The Apex base unit mounts using keyhole slots on the back. Install the screws first, but don't tighten them all the way. The base unit slides down onto the screw heads.

  • Mount within 6 feet of the EB832
  • Mount in a dry location away from splashes or high humidity
  • Leave space for airflow and cable routing
Mounting the Energy Bar 832

Mounting the EB832 Energy Bar

The EB832 mounts using integrated slots on the back. Install the mounting bracket, then slide the energy bar down onto the bracket.

  • Position it so power cords naturally route downward to help maintain drip loops
  • Keep AC cords separate from probe and data cables
  • Ensure outlets and status LEDs remain visible

Helpful Tools for Mounting

  • Drill and appropriate drill bits
  • Phillips screwdriver
  • Level
  • Tape measure
  • Pencil to mark mounting hole locations

Note: We recommend mounting the Apex to a dedicated controller board. If you're mounting to a different surface, be sure to use appropriate anchors.

 

Plugging Everything In

 

With the base unit and EB832 mounted, the next step is connecting the probes, sensors, and Aquabus cable. Follow the steps below and you'll be up and running in no time!

Apex probes and sensors connected to the base unit and EB832
  1. 1

    Temperature Probe

    Plug the temperature probe into the temperature port on the Apex base unit.

    • Keep probe cables separate from AC power cords when possible.
    • Place the probe in a high-flow area of the sump for consistent readings.
    • Avoid installing the probe in the return chamber as evaporation can expose the probe and cause false readings.
  2. 2

    pH Probe

    Plug the pH probe into the pH port on the Apex base unit.

    • Keep probe cables separate from AC power cords when possible.
    • Plan for easy access later for calibration and maintenance.
    • Avoid installing the probe in the return chamber as evaporation can expose the probe and cause false readings.
  3. 3

    LD-2 Leak Detector

    Plug the LD-2 leak detector into an available FMM port on the Apex base unit.

    • Place the sensor where leaks would be detected early.
    • Concrete surfaces can potentially cause false alarms.
  4. 4

    Magnetic Optical Sensor (MOS)

    Plug the MOS into an available FMM port on the Apex base unit.

    • Mount the sensor at the desired trigger water level, usually in the sump’s return pump chamber.
  5. 5

    Aquabus Cable

    Connect the Aquabus cable between the Apex base unit and the EB832 Energy Bar.

    Note: It doesn't matter which Aquabus port you use on either device, as long as the cable connects the base unit to the EB832.

One Last Thing

Apex Fusion is Neptune Systems' free cloud-based service that lets you monitor and control your Apex from where ever there's an internet connection. It works on Windows or macOS via web browser or on your tablet or smart phone via the Apex Fusion app that's available for both iOS and Android devices.

Need More Info About How to Set Up Your New Apex in Apex Fusion?

Check out this guide: How to Get the Neptune Systems Apex Set Up in Apex Fusion (Coming Soon!)

 

 

Frequently Asked Questions About Apex

 
What is the A3 Apex, and what does it actually do for my aquarium? +

The Neptune Systems A3 Apex is an aquarium controller that monitors key tank parameters, controls connected equipment, and sends alerts when something isn’t right. It can track things like temperature and pH, turn equipment on or off automatically, and notify you if a problem occurs, helping keep your aquarium stable and protected.

What’s the difference between the A3 Apex and the A3 Apex Pro? +

The standard A3 Apex focuses on core monitoring and control, including temperature and pH. The A3 Apex Pro adds more advanced monitoring capabilities, such as ORP, along with additional sensors and a port for adding a salinity probe.

Is the A3 Apex difficult to set up for beginners? +

The A3 Apex can be as simple or complex as you want to make it. Basic setup involves mounting the hardware, plugging in probes and sensors, and following guided steps in the Apex Fusion app. You can start with simple monitoring and alerts, then add more automation over time as you become more comfortable.

What happens if my internet or WiFi goes down? +

If your internet connection goes down, the A3 Apex continues running locally and will still control equipment based on existing programming. You will lose remote access and cloud alerts, but core functions like turning outlets on or off and following schedules continue uninterrupted.

Can the A3 Apex really help prevent equipment failures or tank crashes? +

Yes. The A3 Apex helps reduce risk by monitoring conditions around the clock and alerting you to issues like temperature swings, power problems, or water leaks. While no system can guarantee against every failure, having real-time monitoring and automated responses can significantly improve reaction time and overall tank safety.

Are Aquabus cables the same as regular USB cables? +

No. While Aquabus cables use the same physical connector as a USB cable, they are not standard USB cables and should never be connected to a computer or non-Apex device. Aquabus cables are designed specifically for the Neptune Systems A3 Apex to provide power and communication between the Apex base unit, the Energy Bar, and expansion modules. Using a standard USB cable in place of an Aquabus cable, or plugging an Aquabus cable into a computer, can cause equipment damage.