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"Apex ATK" Controllable Aquarium Auto Top Off System
"Apex ATK" Controllable Aquarium Auto Top Off System
"Apex ATK" Controllable Aquarium Auto Top Off System
"Apex ATK" Controllable Aquarium Auto Top Off System

"Apex ATK" Controllable Aquarium Auto Top Off System

Brand: Neptune Systems
Item Number: NPTN-APEX-ATK

Regular price $199.95 On Sale

Only 2 left in stock!

Estimated Arrival: Between Jan 22 and Jan 28. *ETA for USA only. For accurate lead times, call us at 727-214-7750

Large, Custom, Or Backorder: Arrival Times May Vary.

Shipping Policy: Little or No Shipping Charges for Regular-Sized Items; We Cover Part of the Freight Costs for Large Items Shipped Nationally. See Shipping Policy.

Function: Safely and reliably combat evaporation and automate water top offs in your aquarium with 4 fail safes, the most out of any ATO system available. This eliminates the need to ever carry top off jugs to top off the aquarium.


  • One piece ready installation to easily operate right out of the box
    • Eliminates the massive pile of parts, pieces, and long instruction manuals and setup times inherent with any other ATO systems
  • FMM (Fluid Monitoring Module) acts as the brain that drives the ATK and its accessories, and allows the ATK system to be used completely standalone of an Apex System
    • Monitors all sensors 24/7
    • Tells the pump when to turn on and off based on current water level
    • Sounds an audible alarm and shuts off the system automatically when something goes wrong
    • Can connect easily to an Apex with its Aquabus port
  • PMUP (Practical Multi-Purpose Utility Pump) 
    • Able to push water up to 14 feet
    • Allows the ATO reservoir to be in a separate room, even downstairs from the display tank
    • Easily serviceable with full 5 second disassembly for maintenance
  • Water Level Mechanism actively senses current water levels with 4 Fail Stages (no other ATO currently has this any redundancies)
    • 1st Optical Sensor
      • Sits at the normal water level and senses when water is below it, and then tells the PMUP utility pump to turn on and fill the reservoir
    • 2nd Optical Sensor
      • Mounted slightly higher than the first sensor with the same function as a backup if the first sensor fails
      • When the second sensor is used instead of the first (because of sensor failure), the FMM module will sound an audible alarm
      • If connected to an Apex system, you will receive a mobile alert
    • IQ Fill Electronic System
      • Logs all the reservoir fill times required in your aquarium systems history
      • Makes a running average of all of these fill times together to create an average fill time for your specific aquarium system
      • Creates an Auto Shutoff Fill Time a few seconds after your average fill time, so that if the pump is ever on longer than that, the system automatically shuts off, sounds an alarm, and sends an alert
    • Float Valve Safety
      • Oldest and most tried-and-true tested way to monitor and regulate water levels
      • Acts as a final safety if all else fails
  • Optional Accessory Upgrades for the additional two slots on the FMM
    • Additional Optical Sensor
      • Mount at the base of your reservoir
      • Whenever the water level drops below the sensor, the PMUP will be automatically shut off and an alarm will sound telling you to refill
      • Prevents the pump from ever running dry
    • Leak Detection Probe
      • Position at the base of the tank or sump system
      • If there’s ever a leak, the probe will detect it and the FMM will sound an alarm and send an alert

Here is a video where Terence from Neptune Systems gives us a complete walkthrough of the Apex ATK including Equipment Rundown, 3 Level Fail Safe Overview, Complete Setup Demonstration, and Multi-Alarm Walkthrough. Thanks Terence!

Here we can see the Story of Neptune Systems, from Humble Beginnings, to Massive Improvements to become the aquarium controller powerhouse they are today.

Have any further questions that aren't answered here? We'd love to hear from you, and learn how we can help you be as successful as possible in this wonderful hobby.

You can call in to 727-214-7750 to speak with Tyler from our team to determine how to create your Ideal Aquarium Build.

Also feel free to reach out to us at and we will aim to respond back within the next few hours.


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