1.5" (3.81cm) Digital Flow Meter

What the DFM-3 Does

The TrolMaster DFM-3 is a 1.5-inch digital inline flow meter designed to accurately measure water or nutrient solution moving through a fluid pipe. It sits in-line on your main irrigation header and continuously tracks volumetric flow in real time, displaying readings locally on its integrated LCD screen.

Its primary function is to feed live flow data to the TrolMaster Aqua-X Pro (NFS-2) controller. When the DFM-3 is connected to the Aqua-X Pro, operators can switch their irrigation scheduling from time-based to volume-based — meaning every feed event delivers a specific, measured volume of solution rather than running for a fixed duration. For commercial operations where consistent plant inputs directly affect uniformity and yield, this distinction matters.

Beyond core flow measurement, the DFM-3 is engineered to support expanded future functionality, including potential water leak detection and line blockage sensing — adding a layer of system-health visibility to your irrigation infrastructure.

Who This Is For

The DFM-3 is the right sensor for licensed cannabis and hemp cultivation facilities already running — or planning to run — the TrolMaster Aqua-X Pro (NFS-2) irrigation control platform. It is the largest pipe-size option in the TrolMaster DFM series, making it the appropriate choice for facilities with 1.5-inch main irrigation headers: typically mid-to-large commercial rooms with higher flow demands, multiple zones fed off a central manifold, or operations running high-volume fertigation through a single pump circuit.

If your facility is currently scheduling irrigation by time alone, integrating the DFM-3 with an Aqua-X Pro controller is the straightforward path to volume-controlled feeding without a full system overhaul. Growers running coco, rockwool, or recirculating hydro setups where precise shoot volume matters most will see the clearest operational benefit.

The DFM-1 (1") and DFM-2 (1.25") cover smaller header sizes in the same product family — size selection should match your existing pipe diameter.

Key Features

The DFM-3 includes an onboard LCD display for on-site, real-time monitoring of flow rate without needing to reference the Aqua-X Pro controller interface — useful during setup, maintenance, or manual system checks.

Volume-based feed control is the standout integration feature. When connected to the Aqua-X Pro controller, the system can trigger irrigation start and stop based on total volume delivered rather than elapsed time. This compensates automatically for pump pressure variations, partially clogged emitters, or line pressure drops that would otherwise cause time-based schedules to over- or under-deliver.

Environmental ratings — 32–122°F operating temperature and ≤90% relative humidity — make the DFM-3 suitable for the ambient conditions common in commercial grow rooms and fertigation rooms. The unit ships as a single 1.5" digital inline flow rate meter ready for in-line installation.

How It Fits a Commercial Build

The TrolMaster Aqua-X Pro (NFS-2) is a fully modular, scalable irrigation control platform capable of managing multiple irrigation solenoids, pumps, and sensors — including pH, EC/PPM, temperature, and water content sensors — from a single controller. The DFM-3 slots into that ecosystem as the flow measurement node on a 1.5-inch supply line.

In a typical commercial configuration, the DFM-3 is installed inline on the main fertigation feed before it branches to zone solenoids. The Aqua-X Pro reads real-time volume data from the meter and executes each irrigation event against a target volume setpoint rather than a timer. Combined with the NFS-2's expanded scheduling capabilities — up to 50 individual daily irrigation schedules — this setup gives a head grower precise, repeatable control over every feed event across every zone.

HSC supplies TrolMaster equipment nationally to licensed operators. Contact us for a quote on the DFM-3 or to discuss a complete Aqua-X Pro system build for your facility.