IMPROVING YOUR GREENHOUSE
Our LED grow lights are some of the most powerful LED lights in the industry, watt for watt. Not only do we use high efficiency diodes, but we then put them behind a secondary optical lens that magnifies the diode’s light downward, achieving unparalleled canopy penetration. Due to this intense light concentration, the hanging height above the canopy needs to be taken into consideration when finding the light’s ‘sweet spot’. With the K3 series, all diodes utilize 3 watt chips, and the ‘sweet spot’ for this series of lights is 30-60 cm above the canopy. This will ensure the right intensity of light is being received and that the maximum footprint is being taken advantage of.
We recommend, that when first introducing LED lights to new plants and clones, the light should be hung 120 cm or more for the first 3-4 days. After this initial break-in period, we then suggest lowering the light 10-20 cm every couple of days until the desired height is achieved.
If you happen to exceed the minimum distance to your plants, there will be certain signs, usually manifesting in the form of slight curling of the youngest leaves on the plant and/or overall slower growth. If either of these is experienced, simply raise the light back up 120-240 cm and wait a few days. The results in backing the light off should be immediate, and you should see the plant return to robust, lush growth within a day or so. If it seems like the plant is still being overwhelmed, back the light off to the top end of the recommended height and allow the plant some time to acclimatize, before trying to lower the light back down.
For best results, warm up your greenhouse!
Using LED lights for growing plants can be very different from using HPS lights for the same purpose. LEDs run cool due to the fact that they emit light solely by the movement of electrons in a semiconductor, or as it is known, the LED chip. Because of this, and the fact that an LED diode is so efficient, they run cool and don’t need a lot of extra equipment to cool them. It also means that very little energy goes unused, resulting in very little excess heat energy.
On the other hand, HPS lights are burning a mix of gases of various elements (xenon, mercury, sodium). This mixture of gas burns at extremely high temperatures in order to produce the massive amount of light that these bulbs emit. The issue with this massive amount of light is that much of it is wasted due to the low absorption rate of certain areas of the spectrum that are the highest energy output and ends up as nothing more than excess heat energy, and lots of it. The heat energy is then absorbed by the plants and results in unusable photons, which then translates into high surface temperatures on the leaves of the plants.
Leaf surface temperatures are also affected by the ambient temperature of the room. The surface of an HPS bulb can reach an excess of 400 C degrees and can warm a room up fairly quickly, even if it’s being properly cooled. The surface temperature of the leaf, and thus the internal temperature of the leaf, can have a huge effect on the rate in which the plant transpires. Transpiration is the mode in which plants control the movement of water out of small pores in the leaves’ surface called stomata. The release of this water vapor through the leaves’ surface is the plants way of not only regulating temperature, but is also the way the plant cycles water and is able to renew its moisture feed via the root system. Think of it as a wicking system. The water leaving the plant is what is creating the force for the roots to pull more in. So, a plant that has healthy transpiration also has a healthy uptake of water through its root system. The healthier the uptake through the root system, the more nutrients the plant can absorb and utilize for rapid growth.
Temperatures within the leaf greatly affect transpiration. The cooler the temperature the less the leaf will transpire. The warmer the temperature, the more it will transpire. Because the surface temperatures on a leaf of a LED lit room can average up to 7 C degrees cooler than a HPS lit room, transpiration can slow, and thus result in slower uptake by the roots and as a result slow growth rates.
Because of this, we strongly recommend raising the temperature of your grow to 28-30 C degrees when growing with LED lamps. This will ensure that the stomata of your plants can fully perform their job and also allow metabolic processes to continue uninhibited for robust growth.
Higher temperatures have other added benefits, and we’ll discuss those in another section.
In the last section we talked about raising the overall ambient temperature of your room to aid in transpiration. Now let’s talk about one of the greatest added benefits to having those warmer temperatures in your room, increased effectiveness of carbon dioxide augmentation.
Carbon assimilation or carbon fixation is the process by which plants convert carbon dioxide from the atmosphere to form metabolically active carbon compounds, such as carbohydrates, by way of photosynthesis.
The ability of plants to absorb carbon dioxide, or assimilation, has been observed to rapidly increase in plants as room temperatures are increased to 28-30 C degrees, up from the typical 22-26 C degrees recommended for HID lit grow rooms. The increase in absorption rate has an enormous effect on growth rate and also on the size of fruits and flowers.
This means that all those heavy carbon dioxide tanks that you’ve been lugging around suddenly have a bigger impact on your yields!