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Neptune Apex ATK V2 Top Off Kit

Original price $690.00 - Original price $690.00
Original price
$690.00 - $690.00
Current price $690.00

If you want a safe ATO system, the Neptune System ATK v2 uses a mixture of optical eyes and a float valve to ensure your tanks water level stays the same while preventing overfills. With the ATK v2 you do not need an Apex Controller since it can be run 100% standalone, however with the addition of an Apex Controller additional features can be unlocked and more accessories can be added to the included FMM module. 

  • Plug & Play Operation
  • Includes Powerful 24V DC PMUP  
  • Two Optical Sensors With No Moving Parts
  • IQ-Fill Water Run-Time Intelligence
  • Mechanical Float Valve
  • Audible Alarms
  • No Apex Necessary
  • Advanced Featured Unlocked When Paired With Apex Controllers


The ATK (Automatic Top-off Kit) is a simple, standalone, and complete solution for replacing water lost to evaporation.

The new aquarium hobbyist has many challenges, but none is more annoying than the chore of adding water, every day, to make up for that lost to evaporation (a.k.a. topping off/up). This alone usually makes the automatic top-off (ATO) device the first piece of automation equipment purchased.

The ironic flip side of this decision is that a faulty ATO device is one of the leading reasons for catastrophic aquarium failure, or even worse, flooding of the house or business.

Not all ATO devices are created equal. Sadly, many ATO on the market are made with cheap components, have very little protection against these catastrophes, and are just a nightmare to assemble and install correctly.

An ATO does not have to be both a blessing and a curse!

Neptune Systems designed our ATK – Automatic Top-Off Kit to not only be super-simple to install and use, but it is unique in the market as an ATO device with three layers of redundant monitoring and water-level control. The ATK does the work for you, while at the same time protecting your tank and your home.


Safer Than You Can See

The Neptune Systems ATK v2 uses the robust Fluid Metering Module with re-designed optical sensors to monitor your water level. The dual sensor design allows for the ATK to have one main water level sensor and the other as a backup should the first ever get dirty. On top of the optical sensors, a mechanical float valve is integrated into the pre-assembled water level mechanism that will protect you against the super rare electronics failure. On-top of all that, IQ-Fill technology will learn and limit the run-time limits for your aquarium system, ensuring that if all else fails, the PMUPv2 never runs long enough to overfill your aquarium. 


Two Accessory Ports Let You Expand Your ATK

The FMM module included with the ATK has four ports for sensors and probes. The two installed optical sensors for the ATK only use port-1 and port-2. This means there are two free ports that can be used for these optional purposes.


Optical Sensors with Magnetic Mounts

Whether for your ATO reservoir, to use as a sump-high alert, or for your long term water storage such as a brute container, these optical sensors plugin into the FMM. In standalone use when used in your ATO reservoir (plugged into port-4), the FMM will stop your PMUP and sound an alarm when the sensor is above the water level. If you plug it into port-3, and mount it high in your sump, if your water level ever goes that high, an alarm will sound and your PMUP will stop operating.


Optional leak detection probes.

Insert one of our leak detection probes into port-3 on the FMM and then place it near your sump. Now, if for some reason your sump should ever overflow, your ATK will stop operating and an alarm will sound.


Flow sensors in sizes from 1/4″ to 2″ (Apex-connected mode only)

Optional sensors are available that will monitor the flow through plumbing on your aquarium. This is perfect for monitoring the health of your return pump, keeping an eye on your emergency drain, setting the levels on your various reactors and filters, or watching the flow to your RODI.



What's Included?

1x FMM Fluid Monitoring Module

2x Optical Water Level Sensors

1x Float Valve

1x 90° Tube Fitting

1x PMUPv2

1x 4 Meters Orange RO Tubing

1x 3/8" to 1/4" Push Connect Adapter Fitting

1x 1/4" Push Connect Siphon Break

1x Set Screw for Non-Float Valve Applications

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