An Extraction Kit for Environmental Control is Vitally Important for Growing Indoors
Nearly every indoor grower knows that plants need light, nutrients and water to grow. Unfortunately, many growers woefully underestimate the importance of the environment.
The gardeners who pay close attention to the environment will always have the most successful grows. It makes a huge difference to plant health and growth speed, both of which will eventually affect the size of the crop. An extraction kit can help a lot with this.
The Key Factors of a great environment:
- The air temperature
- The relative humidity (RH) level in the air
- The level of infrared light
- The carbon dioxide (CO2) level in the air
- The air circulation in the grow space
Without CO2 supplementation, the ideal air temperature an average of between 21ºC and 24ºC over a 24 hour period. If the air temperature is 19ºC for 12 hours during the dark period and then 26ºC during the light period then that gives an average of 22.5ºC over the 24 hour period. Ideall you never want the air temperature to go below 18ºC or else plant growth can stall. Nor should the temperature ever go above 28ºC as this can cause overheating issues. An extraction kit can help keep temperatures in the right range.
With CO2 supplementation the ideal upper and average air temperature is a completely different matter. Both of these can, and should, be higher. The air temperature should still never go below 18ºC. However, the extra CO2 the upper air temperature should be more like 30ºC -34ºC. We will go into this in more detail in the CO2 supplementation section.
The combination of relative humidity and air temperature create something called vapour pressure deficit (VPD). This is a measure of the "drying" ability of the air. If the air is hot and dry, the VPD will be high. This means that plants will lose too much water through the stomata (the breathing pores on the underside of the leaves where they "breath" in CO2 to use in photosynthesis). Eventually the plant will begin to close the stomata which means it will breath in less CO2 which, in turn, will slow down photosynthesis.
If the air is damp and cold, the plant will be barely able to lose water at all. Some water loss is necessary for something called transpiration. This is where water containing nutrients is drawn in through the roots and then some is lost through the leaves. If the water is not lost then no more water (containing nutrients) will be drawn up through the roots. This can lead to nutrient deficiencies. Worse still, damp air encourages molds like powdery mildew and botrytis which can have a devastating effect on a crop. An extraction kit can help with keeping RH within the correct range.
To get the right combination of air temperature and humidity use the chart below and try to stay in the green region:
Infrared light needs to be recognised as something that is emitted by some grow lights (particularly HID lights like HPS). This infrared lights heat up plant leaves directly, raising their temperature by about 1ºC to 3ºC above the air temperature. This is the reason that it is better to use the actual leaf temperature in the chart above than just the air temperature. It is worth mentioning that LED grow lights put out barely any infrared radiation.
Leaf temperature can be measured with an infrared therometer like the IR Pocket Thermometer.
Plants need CO2 for the process of photosynthsis. The background level of CO2 in the air is 300-400 PPM (depending on where you are. Plants can use anything up to 1200 PPM. The higher the concentration in the air, the more that plants can absorb, and the more photosynthesis that can be performed. CO2 supplementation can increase growth rate and yields by about 20%. When supplementing CO2 it is important to raise temperatures by about 5ºC. This is because the extra CO2 makes the plants more resistant to heat stress and it increases the plants' metabolism to increase photosynthesis.
As plants breath in the CO2 in the air, the levels will go down. If you don't supplement CO2 an extraction system will suck out the depleted air and draw in fresh air with normal levels.
While replacing the air in a grow space with an extraction kit is very important, it is also important to use a circulation fan as well. This circulates the air in a grow space to help prevent hot, humid and CO2 depleted microclimates forming around leaves.
Opticlimate full climate control is a great all in one solution for keeping temperature and humidity in the right range.
All our extraction kits include either a rhino or CarboAir carbon filter. These 2 top brands use the best carbon in the world which makes them the best filters in the world. Their unique reliability gives you, the grower, the peace of mind that you need. For more information about which kit is best for you, please see our guide: Choosing an Extraction System
To see our full Duct Fans, Carbon Filters & Air Control range, click here