SMSCOM Twin Fan Controller MK2

The SMSCOM twin fan controller MK2 offers a great range of functionality for such a compact and cost-effective unit. The original SMS fan controllers have been used far and wide throughout hydroponics grow rooms up and down the country. Looking at the sleek design and the reliability they offer it is easy to see why.

The MK2 version of SMS twin fan speed controller builds on everything that made the original great, and sets it in a much more compact and attractive housing. Although it does use pulse width modulation to reduce the fan speed, it does not generate the same level of hum you would typically associate with these type of fan controllers. 

How The SMSCOM Twin Fan Speed Controller Works

There are two versions of this fan controller depending on the total amps of the extraction fans you want to plug into them. One with a maximum of 4 amps and the other with a maximum of 7 amps. Make sure you choose the correct model to cater for the hydroponic extract fans you have or are looking to buy. If you have any problems choosing, please contact us in store and we will be happy to help.

Simply plug your intake fan into the plug socket on the left and your extract into the right-hand socket and you are pretty much there! Then set the minimum fan speed with the left-hand knob, essentially setting the slowest idle speed you want the fans to run at. Then use the right-hand knob to set the maximum fan speed, particularly useful if you choose to oversize the fans in your grow room.

Once the min and max speeds have been set, you need to set the temperature threshold with the knob in the middle. Once this is set, information is sent from the probe to the unit, and it calculates how fast to work. It doesn’t just go to one pre-set speed either, it gradually adjusts the fan speed to gently react to the changing environment, helping to avoid spikes in temperatures.

A lot of growers just opt to have their fans running on full power at all times. Sometimes of the year this can work ok, but other times it will catch you out. The night time temperature has a massive impact on how a plant will grow. In winter, it could quickly get so cold that the metabolism of your plants is affected. Purple stems are usually a good indicator of cold root zone temperatures from a cold night period. Having your fans on a controller that keeps them ticking over on a low speed will usually avoid this problem entirely.

Why Is Temperature Important?

The temperature of your grow room directly relates to how much (or little) your plant will be transpiring, and metabolising. Unfortunately, these two things conflict with each other slightly. The higher the temperature the quicker your plant can metabolise, photosynthesise and make more energy to ultimately yield more flowers.

However, the hotter it is, the more the plant needs to cool itself. At a certain point the plant will not be able to adequately cool itself and will start to suffer as a result. Wilting, tip burn or leaf drop may all begin to occur, all leading to a bad finish.

Controlling the temperature to a point where the plants metabolism is nice and high, and it can still comfortably cool itself is the aim of the game when it comes to controlling your grow room environment.

How Does Temperature Control Work?

The daytime and the nighttime temperatures, should not really be looked at as separate entities. The difference between these two temperatures can induce different responses in the way your plant will grow. The ability to manipulate the difference between these temperatures can give you more control over your plant throughout your entire grow.

A smaller temperature difference will promote the growth energy in your plant to go into vegetative growth. For example, 24 degrees C during the day and 24 degrees C during the night, is perfect for a mother/propagation room to encourage nice healthy vegetative growth.

A larger temperature difference will encourage your plants to put their energy into flower production. For example, a temperature of 28 degrees C in the day and 20 degrees C at night will encourage more flowering growth.

In the last week or so of flower, you can also use a larger than normal temperature drops to encourage a more colourful display in your flowers come harvest time. A wider range of colouring will usually be seen but be careful not to go too low that plant metabolism is too badly affected.

Tips For Use

If you are using it to control an intake and an outtake fan at the same time, make sure you size the intake fan appropriately, so you do not end up with a positive air pressure inside your grow room.

Always monitor your temperatures with a separate thermostat, to double check that everything is running according to plan. You will need to adjust your settings over time as your plants grow.

If you are having problems with cold night time temperatures and your fan can’t go any slower, consider investing in a good grow room heater to bring the temperature back up to acceptable levels.