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Winter is coming...





Intake Temperatures

The short but sweet summer has started to fade away again, leading us into the cooler months of autumn and winter. As temperatures start to fall outside, the temperature of your air intake will naturally decrease. When the temperatures of your intake become cold, having the intake fan pushing air into the bottom of your tent can cause problems as your plant’s roots can become too cold. During these colder months, it is actually very beneficial to have your intake higher up so that the cold air is falling onto your plant’s canopy. This way the cold air will mix with the hot air and create a much more even temperature throughout the grow space and most importantly will keep your plant’s root system from becoming too cold. When the roots of a plant become too cold it decreases the speed at which water and nutrients can be taken up and can even stop taking on water if the temperature is cold enough. Using an air distribution hose to disperse the cold inlet air helps to create an even more consistent temperature throughout the grow space as the cold air is dispensed from multiple holes along the hose creating a better diffusion and spread of cold air over your canopy.


Cold Nights

The use of a tube heater along the floor of your grow space will stop any cold snaps that may occur when the lights in your grow space turn off. These well-designed heaters fit perfectly between your pots, supplying your plants with a gentle heat from the floor so that the heat rises up into your canopy. 


When the lights in your grow-space turn off and the temperature drops, heaters that you may have in the room will turn on to compensate for the fall in temperature. If your extractor fans are working at the same speed as when your lights were on the heat produced by the heaters will just be extracted as quickly as it is being produced. This is an incredible waste of power and therefore money. Using a thermostatically controlled fan speed controller to maintain the temperature of your grow space will decrease the speed of your extraction when temperatures fall and it will increase the speed of your extraction when temperatures increase. The RAM Air Pro is a very easy to use plug and go fan speed controller with three control dials. One controls the desired temperature which is displayed on a digital display, one controls the minimum speed at which you would like your extractor to run at and the final dial controls the balance between the intake and extractor fans so you can maintain negative pressure even if you have different sized intake and extractor fans.  Monitoring your maximum and minimum temperatures will help you to tailor your fan speed settings and room set up to maintain the evenest temperatures possible using a Min/Max Thermometers. Using a combination of tube heaters and a thermostatically controlled fan speed controller will stop your grow room from becoming too cold during the night time period. As the temperature falls within the grow area, the heaters will turn on and the fan speed controller will decrease in extraction rate, conserving the heat being given off by the heaters. Just using a thermostatically controlled fan speed controller will help to create a more stable temperature within the grow area when lights are on, but when the lights go off you are at the mercy of your intake temperature.  Additionally, "Heat" from vitalink is an advanced bio-stimulant which increases plant resistance to temperature decreases below 5 degrees celsius/frosty conditions and helps it to thrive through the winter months.


Keeping Young Plants Happy In Cold Times.

Propagating cuttings and starting seeds can be a bit more challenging during the colder months if you do not have the right products to maintain stable temperatures. The use of a heat mat and thermostat can be of great help to stop those newly developed roots from becoming too cold which would slow development of roots and shoots. A Heated Propagator can also benefit young vulnerable  seedlings. 


Cooler Weather = More light

The colder weather outside also allows you to use more or higher powered HID lighting whilst maintaining the same desired temperature. Areas which housed a 250w HID light during summer may be able to cope with a 400w, whilst a 400w model could be changed to a 600w. Having a dimmable ballast allows you to have one ballast to power a 250, 400 or 600w bulb so you can use the same ballast whatever temperatures or area you are contending with. 

The Maxibright 400v 1000w Digilight Pro Max is a favourite here at Green spirit. Coupling the 400v 1000w Maxibright Digilight Max with the 1000w double ended Phillips Green Power Plus bulb and a Sunlight Systems AC/DE  Air Cooled Reflector creates a lighting kit of unrivalled performance. Due to its air-cooled design, this lighting kit can be used in the same area that a non-air-cooled 600w light would usually be whilst maintaining the same desired temperatures. 

If air-cooled lighting was in place during the summer months, the lenses can be removed, or reflectors changed to non-air-cooled which allows more light to reach your plants.

Humidity in Relation to Temperature.

Humidity during the colder months will as a general rule increase outside the grow room but temperatures have decreased, meaning that the air itself cannot hold as much moisture. When you draw in air during the warmer months, the air temperature only increases by around 5- 10 celsius so you will only see a slight decrease in relative humidity as the air warms up in your grow space (eg. 60% outside air down to 50% when warmed in grow space). When you are drawing in the much colder air you will see a much more noticeable reduction in relative humidity (80% outside down to 50% when warmed) as the air is warmed up inside the grow space as the air will increase by 10-15 celsius. To create areas of high humidity for vegetative growth during summer and winter months alike, you can use a humidifier, ideally with a humidistat. Browse our humidification section for more helpful products. 

Water Temperatures

When administering or storing water for your plants it is essential to maintain water at the correct temperature, as roots are very sensitive to hot and cold swings. Using water that is either too hot or too cold can stress your plants, cause damage and lead to slow growth. If you use a barrel or large container to mix and store your nutrient solution, the colder temperatures of autumn and winter can decrease the temperature of the solution to a point where it is too cold for plants to uptake. On the other hand, water that becomes too warm can also cause problems, especially in recirculating systems. As the temperature of water increases, it’s capacity to hold dissolved oxygen decreases. This can cause anaerobic organisms to become the dominant power in your root zone and they are the main causal factor when it comes to root disease such as pythium. Keeping your nutrient solution in your grow area can lead to these high water temperatures if the grow room temperatures are exceeding 20 celsius, which most indoor grow rooms will. Keeping your nutrient solution in a cold area with a water heater in your barrel will maintain the perfect temperature so that your plant’s roots don’t become too cold to uptake the water and nutrients or become too warm and susceptible to root disease.  

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