ATK V2 Auto Top Off Kit – Neptune Systems

(3 customer reviews)



In stock

Certified (#AQ0358037) Department of Agriculture


ATO That Is Full, Easy, and Standalone!

The Neptune System ATK v2 combines a combination of optical eyes and a float valve to guarantee that your tank’s water level remains constant while limiting overfills if you want a safe ATO system. Since the ATK v2 may operate completely independently, an Apex Controller is not required. However, with an Apex Controller, more functionality can be enabled and other accessories can be attached to the built-in FMM module.

  • Operation via Plug & Play
  • Powerful 24V DC PMUP is included.
  • Two Moving-Free Optical Sensors
  • Water Run-Time Intelligence with IQ-Fill
  • Automatic Float Valve
  • Hearing Alarms
  • No Apex Is Required

When paired with Apex Controllers, Advanced Features are Unlocked.

The Automatic Top-off Kit (ATK) is an easy, independent, and comprehensive way to replenish water lost to evaporation.

The daily task of topping off or topping up an aquarium, also known as adding water to make up for water lost to evaporation, is one of the most frustrating problems for a beginner aquarium hobbyist. The automated top-off (ATO) device is frequently the first piece of automation equipment acquired due to this factor alone.

Ironically, this approach has the unintended consequence of making malfunctioning ATO devices one of the main causes of catastrophic aquarium collapse or, even worse, flooding of the home or place of business.

ATO equipment varies greatly in quality. Sadly, a lot of ATO on the market are constructed from subpar materials, offer no defense from these disasters, and are simply impossible to adequately assemble and install.

It’s not necessary for an ATO to be a blessing and a curse.

Our Automatic Top-Off Kit (ATK) from Neptune Systems is unlike any other ATO device on the market since it has three redundant levels of monitoring and water-level management in addition to being incredibly easy to install and use. The ATK takes care of the task while also safeguarding your home and tank.


Your water level is monitored by the Neptune Systems ATK v2 using a reliable Fluid Metering Module and newly created optical sensors. The dual sensor architecture enables the ATK to have one primary water level sensor and one backup sensor in case the primary one ever becomes contaminated. The pre-assembled water level mechanism includes a mechanical float valve in addition to the optical sensors as protection against the extremely unusual electronics failure. And if all else fails, the PMUPv2 will never run long enough to overfill your aquarium since IQ-Fill technology will learn and limit the run-time limitations for your aquarium system.


For sensors and probes, the FMM module that came with the ATK includes four ports. Only ports 1 and 2 are utilized by the ATK’s two optical sensors that are installed. This indicates that two free ports are available for usage with these optional uses.


These optical sensors fit into the FMM and may be used for your ATO reservoir, as a sump-high alarm, or for your long-term water storage, such as a huge container. When the sensor is above the water level, the FMM will stop your PMUP in standalone mode when it is hooked into port 4 of your ATO reservoir. If you mount it high in your sump and plug it into port 3, your PMUP will cease working and an alert will ring if your water level ever rises to that level.


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.


You may purchase extra sensors to keep an eye on the water flow via your aquarium’s plumbing. This is ideal for checking the condition of your return pump, observing the flow to your RODI, adjusting the levels on your different reactors and filters, and keeping an eye on your emergency drain.


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