Neptune Systems

A3 Apex Jr Controller System

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Neptune Systems A3 Apex Jr System -- Get the essential monitoring you need now, expand into control later

  • A3 Apex Jr base unit
    • 2 FMM Ports
    • 2 Aquabus Ports
    • 1 pH probe port
    • 1 Temperature probe port
    • WiFi compatible only (no Ethernet port)
    • New built-in audible alarm
    • Expandable
  • Track temperature and pH with included lab-grade, double-junction probes
  • Monitor water level with new MOS Magnetic Optical Sensor
  • Stay on top of leaks with LD-2 Leak Detection Floor Sensor
  • Set reminders, log testing and dosing information, and access your tank from anywhere
  • Affordable entry into Apex ecosystem with ability to add-on/expand as you see fit



The Apex Ecosphere-- Less Hassle, More Success

Built in WiFi, key parameter monitoring, and reliable equipment control. Prevent catastrophes, take corrective actions, and receive alerts to your smart phone when things go awry. Set reminders, log testing and dosing information, and keep tabs on your aquarium from anywhere in the world. All this and more is possible with the Neptune Apex Controller System!

The Apex's included WiFi allows you to connect to the free Fusion Cloud interface, where you can do everything from calibrating probes to customizing outlets with just a few taps. Fusion also gives you the ability to monitor and control your Apex from anywhere and on nearly every device platform – computer, tablet, or smart phone – Windows, OSX, iOS, or Android.

The Fusion interface has a user-friendly design sure to create a headache-free command center for all your aquarium automation needs. Its drag and drop interface allows you to toggle control switches, graphs, video tiles and more to your dashboard, allowing for easy customization that is focused on your individual monitoring needs. Being that the Fusion is a web-based application, you will never have to endure the rigmarole of endless app updates, clumsy touch screens, or complicated drivers to install. Whenever you open the interface, you are always running the most current version of the software. Set up and configuration is streamlined with an easy-to-follow guided user interface.


A3 Apex Jr Base Unit

The A3 Apex Jr is an affordable, entry level monitoring-only solution that keeps tabs on only your most essential tank needs. Track temperature, pH, water level, and floor leaks while keeping the door open to further monitoring and control options down the line.

The Apex Jr features two AquaBus ports that will allow you to connect to additional modules and accessories to continue building out your control system. Want to add Salinity monitoring? Just connect a PM2 module. Need Dissolved O2 monitoring? Simply add a PM3. How about control and monitoring of pumps, lights, and other equipment? Snag an EB832 Power Bar. The opportunities for expansion are endless.


*NEW* MOS Magnetic Optical Sensor

The Neptune MOS replaces the previous OS-1-M and features an updated design that fits into tighter spaces and helps to prevent water incursion into the sensor. The MOS plugs into an Apex FMM port and, using reflected infrared light, will signal your Apex when it changes state from being wet to dry or dry to wet. This sensor can be used for constructing your own ATO (auto-top-off), as a high-level warning sensor in your sump, water storage level sensor, and much more. The sensors can be mounted on any type of reservoir that has up to 1/4" thick walls. 


LD-2 Surface Leak Detection Sensor

Neptune's LD-2 is a full sized leak detection probe perfect for inside your stand, on hard floors, on top of skimmer cups, or any other flat surface where an overflow may cause issues. If water ever touches the sensor, your Apex Controller will be instantly notified so you can take corrective action and avoid disaster.


Lab Grade, Double Junction Probes 

The Apex system includes high-quality probes for monitoring your tank's temperature and pH. Calibration is a quick and simple process via the app dashboard, which will automatically recognize when your readings have stabilized and letting you know when to move to the next step-- no more guesswork and reading RAW data. In addition, the double junction pH probe will allow your readings to stay more stable without the need to calibrate as often. 



A3 Apex Bundle Includes:



Note: Apex Display Module, Smart Phone, and Tablet not included.

More Information
SKU 251247
UPC 653078004977
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Product Questions

Can you use a fmk kit with this?
Question by: Scen Pflug on Apr 21, 2023, 5:56 AM
Yes you can use this with the FMK.
Answer by: Tyler Schafer (BRS Staff) on Apr 21, 2023, 12:08 PM
This can be used with the FMK.
Answer by: Tyler Schafer (BRS Staff) on Apr 21, 2023, 12:13 PM
This can be used with the FMK.
Answer by: Tyler Schafer (BRS Staff) on Apr 21, 2023, 12:28 PM
Can I use an EB8 with this?
Question by: Ryan on Oct 17, 2022, 8:58 PM
Yep! You can add an EB823 to the JR,
Answer by: William Reed (BRS Staff) on Nov 2, 2022, 10:37 AM
Does APEX Jr work with DOS system, or does that require another piece of hardware?
Question by: Tony O on Oct 5, 2022, 4:53 PM
yes, the DOS will connect to one of the two aquabus ports on the A3 APEX Jr.
Answer by: William Reed (BRS Staff) on Oct 6, 2022, 9:58 AM
Can you use the Trident with the Apex Jr?
Question by: Robert on Aug 30, 2022, 8:19 PM
Hey there,

Yes you can use the a Trident with an APEX JR. You would need a 1Link module though in order to use that and a free aquabus port on your APEX JR. You could then run the 1link cable from the Trident to the 1link module. Or alternatively you would need a free aquabus port on your APEX JR and run an aquabus cable to the Trident and then pick up the 36W 24v DC power supply to power the Trident. Thanks!
Answer by: Codey on Sep 2, 2022, 11:12 AM
Exactly what *can’t* you expand to with the Jr.? Can you, eventually, expand it to have all the capabilities of the standard Apex, or are there certain limitations you’re locked into and functions/expansions/sensors/etc. you can’t ever upgrade to with this unit?
Question by: Eli on Aug 13, 2022, 5:35 PM
Thanks for the question! The A3 Apex Jr can expand to all the modules the A3 Apex/Apex Pro can use, the only sacrifice is that you won't get the same capability out of the box and be limited to a wifi only internet connection with no option for an ethernet connection. You'll save some money by getting the regular A3 Apex, but the Apex Jr will get you started if you want just monitoring for now then control later. Let us know if we can help with anything else!
Answer by: Kyle Thomas (BRS Staff) on Aug 17, 2022, 11:21 AM
I have never used an apex before so i wanted to to know if i get the jr will it also measure salinity
Question by: Rajesh on Aug 12, 2022, 3:59 PM
Thanks for the question! The Apex Jr will not be able to measure salinity out of the box. You'll be able to do so with the additon of the PM2 Salinity Module and salinity probe purchased separately. The A3 Apex Pro will have the port for the salinity port built in, but probe would be a separate purchase. Please let us know if we can help with anything else!
Answer by: Kyle Thomas (BRS Staff) on Aug 17, 2022, 9:20 AM