Neptune Systems

A3 Apex Jr Aquarium Controller System

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A3 Apex Jr: Aquarium Monitoring for All

  • Essential Monitoring of Temperature, pH, and Water Levels
  • Leak Detection Sensor Included
  • Expandable: Add on other Apex Modules to Expand Your System
  • Built-In WiFi & Remote Access via Apex Fusion
  • Notifications when Parameters Fall Outside Set Safe Zones


Why Do I Need an Aquarium Monitor?

An aquarium monitor is a valuable tool for any aquarist. It serves as your eyes and ears, continuously checking and reporting the vital parameters that ensure the health and stability of your aquarium. By keeping track of temperature, pH, water level, and potential leaks, an aquarium monitor:

  • Prevents Disasters: Early detection of abnormal conditions, such as temperature, allows for immediate intervention, preventing potential damage and loss.
  • Saves Time and Money: Automated monitoring reduces the need for frequent manual testing and can help avert costly repairs from unnoticed issues.
  • Enhances Peace of Mind: With real-time alerts and remote access, you can be assured that your aquarium is functioning well, even when you're not home.


Why Should I use the A3 Apex Jr. on my Aquarium?

The A3 Apex Jr is an affordable, entry-level monitoring solution that keeps tabs on only your most essential tank needs. Track temperature and pH plus water level and leak detection to protect your aquarium and home.

The A3 Apex Jr features two AquaBus ports that will allow you to connect additional modules and accessories to continue building out your control system. This gives you the option to add on what you need, when you need it. Want to add Salinity monitoring? Just connect a PM2 module and conductivity probe. How about control and monitoring of pumps, lights, and other equipment? Pick up an EB832 Power Bar.

The Apex Fusion App - Apex Fusion is a free cloud-based service that allows you to connect to your Apex from anywhere in the world! This user-friendly platform allows effortless monitoring of your aquarium's vital parameters. With features like drag-and-drop customization, easy-to-use task functions to set up new equipment, and real-time alerts, Apex Fusion ensures that maintaining optimal conditions in your aquarium is hassle-free and efficient.


What Else Do I get with the A3 Apex Jr?

Aside from the A3 Apex Jr. itself, included in the box are four monitoring probes/sensors that give you temperature, pH, water level, and leak detection.

Temperature Probe: If the temperature falls outside of the specified safe zone, you'll receive a notification so that you can correct the issue. Crucial for detecting malfunctioning heaters early, allowing you to fix the problem before it's too late.

pH Probe: Knowing your aquarium's pH is helpful in a number of ways, but particularly useful if you're dosing two-part or kalkwasser to your aquarium. For example, the pH probe might help you detect a potential overdose due to a stuck dosing pump.

Magnetic Optical Sensor (MOS): This low-profile level sensor can be used for a number of purposes such as a high or low level warning in your sump or dosing container. It can be mounted on any type of material up to 1/4" thick. 

LD-2 Leak Detection Sensor: Protect your floors by placing this sensor inside your aquarium stand or any other flat surface where an overflow may cause issues. If water ever touches the sensor, your A3 Apex Jr. can notify you so you can take action.



What's Included?

A3 Apex Jr Base Unit

Power Supply

Temperature Probe

pH Probe

MOS Magnetic Optical Sensor

LD-2 Leak Detection Sensor 

Calibration Solutions (7 & 10)

Mounting Screws

Getting Started Card

More Information
UPC 653078004977
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Product Questions

Is the A3 Apex Jr Aquarium Controller System compatible with the new DOS Quiet Drive Doser?
Question by: Darrell on May 9, 2024, 5:51 PM
Answer by: Tyler Schafer (BRS Staff) on May 10, 2024, 10:04 AM
Will I need something in addition to the Apex Jr (other than the cord) to control my dimmable Aquatic Life Hybrid T5HO fixture?
Question by: Nancy MacCrae on Mar 9, 2024, 4:36 PM
The Apex Jr. unfortunately does not come with a 0-10v output built in, so you will need this module here in order to control your lights with it: https://www.bulkreefsupply.com/led-pumps-control-module-vdm-neptune-systems.html
Answer by: Laura (BRS Staff) on May 2, 2024, 5:41 PM
So if I want to use this with everything it comes with but also the core pump and Neptune ato system, what all else do I need to buy to make it all work?
Question by: Sven Pflug on Dec 24, 2023, 7:09 AM
Hey there, you would either need an EB832 or a 1link module. Thanks!
Answer by: Codey on Jan 8, 2024, 1:18 PM
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