Replacement and Backup Temp / Humidity / Light Sensor for Hydro-X

What the MBS-TH Is

The TrolMaster MBS-TH is the 3-in-1 temperature, humidity, and light sensor designed exclusively for the Hydro-X environmental control system (HCS-1). It measures ambient air temperature, relative humidity, and light presence via a built-in photocell that the controller uses to detect and automate day/night transitions.

Each Hydro-X controller ships with one MBS-TH sensor included. The MBS-TH SKU exists for two purposes: as a direct replacement when your original sensor fails or is damaged, and as an additional sensor to extend environmental monitoring to a second location within the same grow space — useful in larger rooms where a single sensing point doesn't capture the full picture.

This sensor uses the same RJ12 bus architecture as the rest of the Hydro-X accessory ecosystem, so installation is straightforward: run the cable, plug it in, and the controller recognizes it automatically.

Who Should Have One

Any licensed cannabis or hemp operator running a TrolMaster Hydro-X (HCS-1) controller should keep at least one MBS-TH on the shelf. Environmental control is mission-critical in a licensed facility — a failed sensor can force manual overrides or leave HVAC, dehumidification, and lighting automation running blind until a replacement arrives.

Facilities running back-to-back harvest cycles, where any unplanned downtime compounds into real yield loss, benefit most from having a spare. Multi-room operations that want to monitor a second zone — a veg room, a mother room, a dry/cure anteroom — will also use an additional MBS-TH to give the Hydro-X a second data point without investing in a full controller upgrade.

Note: If you are running the Hydro-X Pro (HCS-2) or Hydro-X Plus (HCS-3), those systems use a different sensor (MBS-PRO, 4-in-1 with CO2 and LCD). The MBS-TH is specific to the HCS-1 Hydro-X platform only.

Key Features

Three sensing functions in one housing: air temperature, relative humidity, and a photocell for day/night mode detection. The photocell allows the Hydro-X controller to automatically transition between day and night program settings based on actual light presence in the room — not just a clock timer — which is useful when light schedules shift across a multi-room facility.

Plug-and-play RJ12 connection means no wiring or crimping required. The included 16 ft RJ12 cable provides enough reach to position the sensor in the canopy zone rather than at the controller location, and the included T-splitter allows daisy-chaining additional accessories on the same port without losing a connection point.

The sensor operates within a working environment of 32–122 °F and up to 90% relative humidity, covering the full range of conditions found in active grow rooms, including the high-humidity ranges typical of clone and early veg stages.

How It Fits a Commercial Build

In a properly configured Hydro-X room, the MBS-TH is the nervous system feeding the controller its decision-making data. Temperature and RH readings from this sensor trigger HVAC, dehumidifier, humidifier, and CO2 device stations. The photocell input drives the day/night logic that controls lighting schedules and any environment setpoints that differ between light-on and light-off periods — VPD targets, temperature differentials, dehumidification intensity.

For commercial operators, the practical recommendation is simple: buy the MBS-TH when you buy or commission the controller. A sensor failure without a spare on-site means placing an order, waiting for delivery, and running your room manually or with degraded automation in the meantime. The MBS-TH is a low-cost insurance policy on a control system that may be managing tens of thousands of dollars worth of crop.

Sensor placement matters in larger rooms. If your Hydro-X controller is wall-mounted at the room perimeter, the 16 ft cable gives you enough run to position the sensor mid-canopy where temperature and RH are most representative of what your plants are actually experiencing — not what the air near the wall reads.