Digital Humidistat HR15 / HR50

Once you have purchased your humidifier, the next battle is to correctly control it! The Faran digital humidistat is the finest control unit you can find for a humidification system. Boasting an extremely high level of accuracy, there is no better option for your hydroponic grow room.


A highly sensitive probe is placed in your grow room at a point you would expect represents the most uniform and consistently average levels of the whole environment. Usually towards the middle of your room, just below canopy level. The probe takes readings of the environment for both temperature and relative humidity. These readings are then fed to the main control unit, which reacts to this input based on the levels you have pre-set it to operate at.

If the probe senses relative humidity has dropped below the threshold you have set it to, then the control unit tells the humidifier to switch on. The humidifier will then operate until the probe registers that the humidity has once again gone back up to the programmed set point.

Other parameters can be controlled with the unit, such as the hysteresis. This is particularly useful in different sizes of rooms or grow tents. For example, you may want a quicker response in a smaller room than you would in a larger one, or vice versa, depending on overall conditions. It is also possible to control a heater with the unit. As such, the Faran digital humidistat offers complete versatility for the modern day hydroponic enthusiast.


In a hydroponics grow room, humidity is possibly the most important aspect of the environment that you can control. It is partly responsible for regulating the amount of transpiration seen from a plant and without adequate transpiration levels your plant will suffer! Too low a humidity will result in your plant transpiring excessively, exceeding the amount supplied from the roots resulting in limp, droopy and floppy plants. Too high a high humidity will result in very low transpiration rates, causing issues with positive root pressure (leading to stretching) and leading to nutrient issues with elements such as calcium.

All sorts of issues can be negated with correct control over your humidity. The Faran digital humidistat offers exactly the sort of controls required to create the perfect environment throughout the plants entire life cycle. Becoming particularly important during the first few weeks when hardening your plants off correctly is of paramount importance.


You should not consider humidity as a standalone variable, as it is directly related to the air temperature. The term ‘Relative Humidity’ is used to take account for this. Essentially the higher the air temperature is, the more water it can hold. Controlling and manipulating humidity on a particularly hot day can often be the difference between your plants suffering with heat stress, or continuing as normal. The Faran digital humidistat offers the capacity to control humidity to exacting requirements, all year round.


Always ensure the probe is placed in a part of your room that gives you realistic reflection of the entire environment. Usually somewhere close to the center of your room just below the canopy, out of direct light.

Make sure the control unit is placed somewhere easily accessible. There is no point having a controller if you can’t reach it to use it!

  • Precision control over humidity
  • External probe for optimal placement
  • Easy to use – plug and play
  • Large digital display
  • Exceptional functionality
  • Designed for hydroponic grow rooms
  • Optional heater controls