Measuring the rate of flow through your aquarium plumbing can be incredibly helpful in a couple of different applications. You can monitor the rate of flow from your return pump to gauge your pump's performance and dial in the flow through your overflow box and filtration. You can also monitor the rate of flow through a UV sterilizer, aquarium chiller, algae scrubber, or media reactor to ensure optimal performance. 

The most accurate and convenient way to monitor flow rate through a system of closed pipes is with the use of a flow sensor and it just so happens our most trusted aquarium controller company, Neptune Systems, has built a set of sensors specifically suited for aquariums. 

Neptune Systems Flow Sensors

Flow sensors are installed in line with your plumbing and contain a small fan, as water moves past the fan the device can record the revolutions per second and ultimately measure the rate of flow. The Neptune Systems Flow Sensors connect directly to the FMM module and can then be accessed via Apex Fusion where you can record flow data over time and get accurate flow measurements.

A Neptune Systems Apex with an FMM module is required to connect and utilize Neptune Systems Flow Sensors. The sensors are available in 4 different sizes (1/4", 1/2", 1", or 2") and can be purchased a la carte or you can purchase the FMK Fluid Monitoring Kit which includes the FMM module, 1" flow sensor, and two 1/2" flow sensors. 

  1/4" Flow Sensor 1/2" Flow Sensor 1" Flow Sensor 2" Flow Sensor
Min/Max Flow Rate 3 - 12 GPH 30 - 250 GPH 150 - 1500 GPH 300 - 3000 GPH
Connection 1/4" compression-style for connecting with RO tubing 1/2" SLIP PVC connections 1" schedule 80 PVC True Unions 2" schedule 80 PVC True Unions


Applications for a Flow Sensor

Note: Never install a flow sensor on your drain for the risk of clogging and slowing down the drain rate. The sensors do have minimum and maximum flow ranges so be sure to size the sensors appropriately.

Return Pump

Install the flow sensor inline between your return pump and the display aquarium. This will tell you how much water is moving into your display. 

  • When return flow drops, it can indicate your return pump is dirty or malfunctioning
  • Achieve the optimal turnover rate through your overflow box to reduce drain noise
  • Ensure optimal turnover rate through your sump

UV Sterilizer

The most valuable application of a flow sensor is with a UV sterilizer because performance is based upon a precise rate of flow. 

  • Achieve optimal flow rates through your UV sterilizer at all times for maximum sterilization benefits
  • Adjust flow accurately to target different rates of sterilization
  • Ensure sufficient turnover per hour through the UV

Closed Loop, External Skimmers, Reactors, and Salt Mixing Stations

The sensor can be used when plumbing a closed-loop to verify you are achieving the desired flow rates and monitor pump performance.

  • Monitor your saltwater mixing station
  • Monitor internal flow and external pump performance
  • Verify you are providing sufficient flow through a chiller, calcium reactor, or algae scrubber
  • Provide optimal flow to your external recirculating protein skimmer
  • Monitor RO/DI water production and automatic water exchange systems