Neptune Systems

FMM Fluid Monitoring Module

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$109.99 $109.99

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Neptune Systems FMM Fluid Monitoring Module

  • Flow Monitoring
  • Leak Detection
  • Water Level Management
  • DC24 Accessory Port


The Neptune Systems FMM Fluid Monitoring Module offers practical solutions for real-world aquarium issues. Compatible with the Apex Aquarium Controller, it has four ports for essential functionalities like flow monitoring, leak detection, water level management, as well as a DC24 accessory port. This module is designed for aquarists who need reliable tools to maintain and monitor their aquarium's health, allowing for the integration of various accessories to address specific needs. With the FMM Module, managing your aquarium's environment becomes more straightforward, allowing you to worry less and enjoy your tank more.


Which Accessories Can You Use with an FMM Module? (sold separately)

Flow Sensors: 1/4" FS25, 1/2" FS50, 1" FS100, 2" FS200

Available in four different sizes, flow sensors can be used to monitor your return pump's flowrate or the flowrate of other equipment like UV sterilizers where a specific flow rate is required.

Optical Sensors: MOS Magnetic Optical Sensor, OS-1 Optical Level Sensor

They can help you build an auto-top-off, monitor the levels in your dosing containers, prevent your return pump from running dry, and even help automate saltwater mixing containers.

Leak Detectors: LD-1, LD-2, LD-3

Simply plug in up to 4 leak detection probes and place them in the area you want to be notified about. 

Water Level Sensors: LLS Liquid Level Sensor

If you need to know the specific water level, the LLS is the right tool for the job. Perfect for ATO reservoirs, dosing containers, and the return section of your sump. LLS Sensors are available in four lengths from 4 to 35 inches.

DC24 Accessories: PMUP, SV-1 Solenoid Valve

In addition to the four sensor ports, the FMM also has a DC24 accessory port and a power supply input. If you wish to utilize the DC24 port, simply add a 36W 24V DC power supply (sold separately).


What's Included?

FMM Module

Aquabus Cable

More Information
UPC 019962171857
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Product Questions

How long is the aquabus cable that comes with this?
Question by: James Bulk on Apr 5, 2023, 2:30 PM
Hello, the aquabus cable with all the products are always 6 feet in length.
Happy Reefing,
BRS Customer service team
Answer by: Alexander Reinartz (BRS Staff) on Apr 7, 2023, 12:05 PM
Does the fmm module work over Wi-Fi or does it need to be plugged into apex pro unit or into an eb32 power supply?
Question by: mark Prieto on Feb 6, 2023, 11:05 AM
Thanks for reaching out! you can run it stand alone for an auto top off but anything else must be run through APEX
Answer by: James Johnson (BRS Staff) on Feb 20, 2023, 12:20 PM
Does this module still work with the A3?
Question by: Lisa Foster on Jan 29, 2023, 4:21 PM
Hey Lisa! It does however depending on the model A3 you get it is already built in!
Answer by: James Johnson (BRS Staff) on Feb 15, 2023, 3:18 PM
I just got a Neptune Apex and would like to add additional optical water sensors but am out of FMM ports in the Apex. Is this product the right way to add additional optical water sensor ports to my Apex?
Question by: Tom L on Jan 10, 2023, 4:56 PM
Hey there,
Thank you for reaching out to us. Yes, that is the correct module to add more optical sensors.

Please let me know if you need anything further and take care!
Answer by: Matt Lucero (BRS Staff) on Jan 12, 2023, 10:43 AM
Can the FMM be used with 2 leak sensors and a flow sensor as the same time or is it one or the other?
Question by: DanL on Dec 16, 2021, 5:10 AM
Thank you for your question. The FMM can accept 4 sensors. You can mix and match any of the sensors on the same FMM.
Answer by: William Glenn (BRS Staff) on Dec 16, 2021, 2:36 PM
What is the Difference between the ALD Module and the FMM Module that comes with the Leak Detection Kit
Question by: Jeff Willard on Nov 9, 2017, 6:39 PM
The ALD module is actually discontinued now, but it functions identically to the FMM module, but with a more limited functionality. The FMM module can have flow sensors, optical sensors, leak sensors, and even a pump attached to it, where the ALD was for leak sensing probes only.
Answer by: Charlie on Nov 25, 2017, 10:27 AM
Do you need a power supply if you have the Apex "Classic"?
Question by: Rory Bellina on May 8, 2017, 10:30 AM
Hey there,

You will not need a separate power supply from the Aquabus cable if you are just using this module for monitoring. However, if you plan to power accessories, you will need a power supply and plug this into the power port.

Happy reefing!
Answer by: Zack on May 12, 2017, 2:45 PM