Heavy Duty Nutrient EC+Temp Sensor, drop-in/in-line compatible

What the PCT-3 Is

The PCT-3 is TrolMaster's current-generation heavy-duty EC and temperature probe, purpose-built for the Aqua-X irrigation control ecosystem. It measures the electrical conductivity and temperature of nutrient solution continuously — giving your controller real-time data on what your plants are actually receiving, not just what you mixed at the reservoir.

This is an updated design over the earlier PCT-2. TrolMaster reduced the probe diameter and shortened its body so it fits directly into standard 3/4" PVC tee fittings — the same schedule fittings already in most commercial grow room plumbing. That means no specialty adapters, no inline housings to source separately. The threaded body seals into the tee and the probe sits in the flow path. You can also drop it into a reservoir or catch tank if your monitoring point is there rather than inline.

Who It's For

Any licensed operator running TrolMaster's Aqua-X or Aqua-X Pro system who wants closed-loop nutrient monitoring. That covers recirculating DWC, NFT, flood-and-drain, and coco/soilless drip setups where knowing the EC at the emitter or the drain point — not just at the tank — matters for dialing in fertigation schedules and catching drift early.

It's also relevant when you're spec'ing a new build or retro-fitting an existing room to the TrolMaster automation stack. Adding PCT-3 sensors at multiple points in the irrigation run (pre-plant, post-plant, drain) gives the Aqua-X controller the inputs it needs to log, alert, and eventually automate dosing corrections. Commercial cannabis facilities running precise VPD and irrigation targets need EC data to match — this is the probe that feeds that loop.

Key Features

The reduced-diameter protective sleeve and threaded body are the standout physical changes from previous generations. The probe installs into a standard 3/4" PVC tee without modification — drill the tee, thread in the probe, done. The shortened length accommodates tight plumbing runs where a full-length probe would foul against pipe walls or manifold hardware.

The 3.6-meter (approximately 11.8 ft) cable gives you enough reach to route from an inline tee to a wall-mounted sensor board without excessive conduit work. Connection is via Mini DIN terminal, which plugs directly into the AMP-2 sensor board (used with the Aqua-X NFS-1 main controller) or the AMP-3 sensor board (used with Aqua-X Pro NFS-2, NFS-3, and Green-X GCS-1). No signal conversion, no intermediate wiring — plug-and-play within the TrolMaster ecosystem.

The improved sensor element delivers more stable, consistent readings over time compared to earlier iterations. In a commercial run where the sensor may stay submerged or in-flow continuously for weeks between cleanings, sensor drift is a real operational issue. TrolMaster's redesigned element is intended to reduce that drift and hold calibration longer.

How It Fits a Commercial Build

In a typical Aqua-X installation, the PCT-3 sits between the nutrient reservoir and the plant zones — usually tee'd into the main supply manifold — so the controller reads the EC of the solution being delivered each irrigation event. A second PCT-3 or PCT-1 at the reservoir gives you a before/after comparison to catch dosing inconsistencies or pump issues before they affect the canopy.

For operators using TrolMaster's Green-X or Tent-X controllers, the AMP-3 board accepts the PCT-3 on those platforms as well, making this probe a single SKU that covers most of the TrolMaster product lineup. If you're building out a multi-room facility and want consistent sensor hardware across rooms running different TrolMaster controller generations, the PCT-3 is the compatible choice. Contact HSC to confirm compatibility with your specific controller configuration and sensor board version before ordering.