Apex Hardware Overview

Here's a quick overview of the Apex hardware family:

Apex controller (sometimes referred to as the "base module" or "brain")
The Apex controller is the primary device that controls and monitors the entire Apex setup. There are two current models:
  • Apex (commonly called the Apex 2016)
  • Apex-EL



The following models are still in use by many people, but are no longer being manufactured:
  • Apex Classic
  • Apex Jr
  • AquaController
Each Apex has a variety of ports to connect various probes that measure certain parameters of your aquarium water. The ports available vary depending of the model of Apex.
  • Temperature
  • pH
  • Salinity (conductivity)
  • ORP
  • Dissolved Oxygen (requires a separate module)
All Apex models have an Ethernet port to connect to a computer network. The current models also have built-in WiFi.

The Apex (2016) has two 0-10v variable ports which can be used to control the speed of compatible pumps or powerheads, and/or the brightness & spectrum of compatible lights.

All Apex models have AquaBus ports which are used to connect and control optional expansion modules. AquaBus cables are standard USB cables with Type A male to Type A male connectors. However, you cannot use any USB cable that contains a signal repeater device. Each module has at least two AquaBus ports, allowing modules can be daisy-chained in any sequence to communicate with the Apex controller. Up to 49 modules can be connected on the current Apex models:

Below is a description of each Apex expansion module:


The 1Link module provides three 1Link ports to control 1Link devices, such as the WAV, DOS, COR-15, or Trident modules. the 4-pin Molex connector 1Link cables combine the communications of the AquaBus cable with 24v power to control motors, thereby eliminating extra cables and extra power adapters. It also includes two 24v Accessory ports using the 2-pin Molex connector to control a PMUP, Solenoid, or GRO light. The 1Link module uses an external 100W 24VDC power adapter, so the total load of 1Link and 24v Accessory devices cannot exceed 100 watts:
  • COR15 ~ 60 watts
  • WAV ~ 30 watts
  • DOS ~ 22 watts
  • Trident ~ 10 watts
  • PMUP ~ 17 watts
  • Solenoid ~ 6 watts
  • GRO ~ 20 watts

The Automatic Feeding System is used to automatically feed your fish with dry pellet or flake food.


The Advanced Sensor Module has a coax connector used to connect Neptune's PAR sensor, one port for a temperature probe, and one I/O port for a breakout box. The ASM is currently only sold as part of the PMK (PAR Monitoring Kit) which includes the PAR sensor. Some people have used the ASM to connect other types of sensors to measure humidity, water pressure, or other industrial uses, but Neptune does not officially support these other sensors.


The AWM (Aqua Illumination Wireless Module) provides wireless control of AI Vega, Hydra, and Hydra FiftyTwo LED Lights.

Breakout Box

The Breakout Box provides wire terminals to connect float switches, toggle switches, magnetic switches, or any other type of switch. These are commonly used to monitor water levels, cabinet doors, etc. The breakout box connects to an I/O port on the Apex controller, or an I/O port on the ASM, PM1, PM2, or PM3 modules.


The COR-15 and COR-20 are variable speed DC submersible return pumps. The COR-15 requires an Apex to run and a 1Link connection, but the COR-20 can be operated standalone without any Apex controller or connected to an Apex with AquaBus. The COR-20 has a separate 24v power adapter.
COR Drivers.png


Older model Apex units came with a Display module, which is a small LCD screen with push buttons used to control, program, and view status of the Apex. Modern Apex models do not ship with the Display module, but are still compatible with it. The Display module can be particularly useful since it can show the current IP address, username, and password for the Apex which is not available through the normal Fusion interface or the Apex Classic dashboard.


The DOS is Neptune's two-head dosing pump. It may be used to dose additives into your aquarium, or can be used for automatic water changes. The DOS may be connected either through a 1Link cable, or through an AquaBus cable and a separate 24v power adapter.


The Dual DOS Reservoir is a two-cylinder dosing reservoir that contains optical switches to monitor the fluid levels. The DDR connects directly to a dedicated communication port on the DOS to provide sensor status.

EnergyBars are multi-outlet controllable power strips, and are the heart of the Apex's ability to turn on and off aquarium devices. There are several models of EnergyBars:
  • EB832 - Provides (8) 120v outlets, (3) 1Link ports, and (2) 24v Accessory ports. It also provides per-outlet power monitoring on the (8) 120v outlets. The EB832 is only compatible with the Apex (2016) and the Apex-EL. All of the 120v outlets on the EB832 are identical and each supports a maximum of 7amps, with a maximum of 15 amps on the 120v AC outlets for the entire unit. Like the 1Link module listed above, the total load of 1Link and 24v DC Accessory devices cannot exceed 100 watts.

  • EB8 - Provides (8) 120v outlets. Outlets 1-3 and 5-7 are solid-state, and support 5 amps each. Outlets 4 and 8 are relay controlled, and support up to 10 amps each, with a maximum of 15 amps for the entire unit. Outlets 4and 8 can reliably operate devices which have very low power draw, which can be a problem for the solid-state outputs.

  • EB6 - Provides (6) 240v outlets, only available in the UK or other countries using 240v.

  • EB4 - Provides (4) 120v outlets. All four outlets are relay switched. Outlets 1, 2, and 4 support up to 8 amps each, but outlet 3 can support a device up to 12 amps, which is unique among all of the other EnergyBar modules. The maximum load for the entire module is 15 amps.

The Fluid Monitoring Module provides four ports which can connect optical water level sensors, flow monitoring sensors, or leak sensors. It also provides a 24v Accessory port (which requires an optional 24v power adapter) to control a PMUP (Practical Multi-purpose Utility Pump) or a 1/4" solenoid. The FMM is included with the ATK (Auto Topoff Kit), FMK (Flow Monitoring Kit), and LDK (Leak Detection Kit). Each of these kits come with the appropriate sensors and accessories.


The GRO is a 20W LED refugium light for macro algae. It can connect to any 24v Accessory port on the EB832, 1Link module, or FMM module using the 2-pin Molex connector. You can optionally power the GRO with the same external 2-pin Molex 24v power adapter available for the PMUP or Solenoid. The GRO has a flexible arm with two mounting options; a flat surface clamp, or a pipe adapter capable of fitting 3/4” or 1” PVC pipes.
GRO Tank Mount.jpg GRO Pipe Mount.jpg


The Lunar Simulation Module provides dim LED lights to simulate the moon above your aquarium. The lights are programmed to follow the actual monthly lunar cycle.


The PM1 (Probe Module 1) has one port to connect a pH probe or ORP probe, one port for a temperature probe, and one I/O port to connect a breakout box.


The PM2 (Probe Module 2) has one port to connect a salinity probe, one port for a temperature probe, and one I/O port to connect a breakout box.


The PM3 (Probe Module 3) has one port to connect a dissolved oxygen probe, one port for a temperature probe, and one I/O port to connect a breakout box.


The Trident is an automated water testing device that measures alkalinity, calcium, and magnesium multiple times per day. It uses 3 bottles of reagents which need to be replaced at a minimum of every 2 months, depending on your selected testing frequency. The Trident is only compatible with the Apex (2016) and the Apex-EL. The Trident may be connected either through a 1Link cable, or through an AquaBus cable and a separate 24v power adapter.


The VDM (Variable Device Module) provides two 0-10v variable speed ports to control up to 4 variable speed pumps or compatible lighting systems. It also has a 9-pin serial port to connect to Aqua Illuminations lighting systems.


The WAV is Neptune's variable-speed powerhead. It has many programmable modes for different water flow patterns. The WAV connects via a 1Link cable which requires either the EB832 or a 1Link module.


The WXM provide wireless control of EcoTech pumps and EcoTech Radion LED lights. EcoTech's newest products are no longer compatible with the WXM, so the WXM has been discontinued.

External Power Adapters
There are a number of available DC power adapters for the Apex family of products:
  • 12v Auxiliary adapter - The 12v DC power adapter is used to directly power the Apex base unit. This can be used in place of the normal method of powering the Apex through an AquaBus connection to another powered module, or it can be used in conjunction with a UPS backup battery to detect power failures when running on battery power. See my tutorial on Apex Power Monitoring for details on how to integrate the Apex with a UPS backup battery.

    12V Aux Power Adapter.jpg
  • 36W 24V power adapter - This 24v adapter can be used to power the FMM for use with any 24v Accessory device, DOS, or Trident when connecting via AquaBus rather than 1Link.

    36W 24V Power Adapter.jpg

  • 24V PMUP/Solenoid/GRO power adapter - This 24v adapter has a 2-pin Molex connector to directly attach to the PMUP, Solenoid, or GRO, allowing any of these devices to be powered without an Apex or compatible Apex module.
    24V PMUP Power Adapter.jpg

  • 100W 24V power adapter - This 24v adapter is used for the 1Link module to supply up to 100 watts for 1Link and/or 24v Accessory devices.

    1Link Power Adapter.jpg
About author
John Halsey is a reefing hobbyist with a Red Sea Reefer XL 425 in his living room since 2018 and has been successful in keeping a healthy mixed reef by following best practices learned here on R2R as well as actively participating in his local aquarist club--PNWMAS--in Portland, Oregon. John retired from his 30-year career in IT support, and put that technical expertise to good use by automating much of his aquarium equipment with an extensive Neptune Apex system.

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Thank you for putting this all together. As always fantastic work!
Really great... thanks for that. All in one place. Ty.
Thank you so much for creating this!!! I’ve been beating my head against the wall, trying to figure this out... I just wish they were compatible with more manufacturers... I really like the EcoTech power heads, and wanted to have everything accessible through one app...
Great run down, very informative and as always great helpful info from the man himself.
SuncrestReef as usual - excellent article. One note - I'm sorry to hear that Neptune discontinued the WXM, many of us use them for Ecotech Vortechs as it's been more reliable than Ecotechs' ReefLink.
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