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.

Specifications

• Monitoring included: temperature and pH, each with a probe in the box, plus water level and leak detection.
• Leak detection: analog, using the LD-2 solid-surface leak sensor supplied.
• Two FMM input ports.
• Two AquaBus ports.
• Networking: 802.11g/n Wi-Fi. There is no hard-wired Ethernet on the Jr — that is an Apex and Apex Pro feature.
• Built-in audible alarm buzzer.
• No mains outlets of its own, no 1LINK outputs, no 24 V DC outputs, no digital inputs and no variable 0–10 V outputs. The Jr is a monitor first; outlet control is added by attaching an Energy Bar.
• Auxiliary power: 12 V DC, 0.7 A, 2.1 mm centre-positive (Neptune part PS12).

What’s in the Box

Neptune do not publish a numbered packing list for the A3 series. The list below is taken from the “Included with” line under each accessory on their A3 Apex Series page and from the “What’s Included?” comparison table on the same page, so it is what Neptune say ships with this model rather than a carton we have inventoried. If anything is missing when yours arrives, message us and we will sort it out.

• A3 Apex Jr base unit.
• Temperature probe.
• pH probe.
• Magnetic Optical Sensor (MOS) — a sealed, magnetically mounted level sensor that reports whether water is above or below the point you fix it at. It mounts on material up to 1/4 inch (6 mm) thick.
• LD-2 solid-surface leak sensor, on a 5 metre (16.3 foot) lead.

Not in the box. An Energy Bar — the Jr is sold as the monitoring unit and its four probes and sensors. No ORP probe, no salinity probe, no Liquid Level Sensor.

Compatibility

• Two AquaBus ports let you add Neptune modules as you need them. AquaBus is plug and play — the system does not need to be powered down to add an accessory, and it makes no difference which port you use or in what order modules are chained.
• Salinity monitoring: add a PM2 probe module and a conductivity probe. The PM2 also brings a temperature port and six digital inputs for float switches and water-on-floor sensors.
• A second pH or an ORP channel: add a PM1 probe module. Dissolved oxygen: add a PM3.
• Outlet control: add an Energy Bar. In India that is the EnergyBar 632, with six switched 230 VAC outlets, three 1LINK ports and two 24 V DC outlets.
• Automatic feeding: the AFS runs off AquaBus and Neptune list it as compatible with the Apex Jr.
• 1LINK equipment — the DŌS QuietDrive, COR return pumps, WAV powerheads, Trident — needs a 1LINK port, and the Jr has none. For the DŌS, Neptune’s own setup guide gives the alternative: a 24 V power supply and an AquaBus cable in place of the 1LINK cable, both sold separately. Check the requirement for any other 1LINK device before you buy it.
• Every module keeps its firmware updated through the Apex, and Neptune’s guidance is to bring the controller to the current firmware before connecting a new accessory — an out-of-date controller will not create the accessory’s outlet.

Warranty & Support

This product carries a 1-year manufacturer warranty on hardware from the date of purchase. Probes are consumable items and carry a 90-day warranty.

Warranty support is handled by us directly. Message our WhatsApp support with your order number and we will diagnose the fault first — most cases are solved by replacing a single part, so you rarely need to send the whole unit. If the item does need to come back, it ships to our Delhi or Pune warehouse, whichever one served your order, and courier cost in both directions is borne by the customer. Your GST invoice is valid proof of purchase for the claim.

Backorder & Dispatch Timeline

This item is stocked to order. Back-orders are consolidated and placed with our overseas suppliers once a month, on the last day of the month, and all such orders are shipped before the 15th of the following month.

Back-orders cannot be cancelled once they have been placed with the supplier. If you cancel before that, payment-gateway charges of 2% plus GST are deducted and the balance refunded. In the rare case a supplier cannot fulfil the item, we will offer you an alternative first, and refund in full with no deduction if you would rather not take it.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number — or email us, if you would rather — and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 72 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.