Choose The Right Intensity Led Grow Lights
By admin
Light intensity or light density varies depending on how bright the light source is (conventionally measured by the wattage of the bulb) and how close the plant is to the light. You can vary intensity by moving the light further away or closer to the plants and by increasing or decreasing the wattage of the grow light bulbs you are using. Some care needs to be taken here as some plants will burn easily if placed too close to a bulb and so increasing intensity would be better managed by purchasing a higher wattage bulb and placing it further away. When thinking about the placement of led grow lights, it is important to note that every time you double the distance between the light and the plant the amount of light reduces by 4 (not by 2). The converse is true when bringing a light closer: Halving the distance will quadruple the intensity of the light.
Plants differ in their tolerance to light intensity. Some plants love to be in the full sun and these plants can usually be placed closer to light sources and can tolerate stronger wattage grow light bulbs. Other plants are more shade loving in their natural environment and can be placed a good distance away from the light source or will be happy with a lower wattage grow light bulb. Generally flowering and fruiting plants will require a higher light intensity.
A note on measurement
Light intensity or density is typically measured in ‘lux’ with one lux being the equivalent of one lumen of light falling on a square meter. However it is important to note that other measures are often used in the commercial plant lighting field such as Photosynthetically Active Radiation (PAR) watt. PAR refers to the spectrum of light that is used by plants in photosynthesis and is measured in micromoles per square meter per second to produce a photosynthetic photon flux density (PPF or PPFD) .
These alternative measures are used because thinking in terms of lumen can be misleading when dealing with non-white light sources (such as LED grow lights) used to stimulate photosynthesis in plants. A blue or purple looking LED grow light for example may not appear to be bright in white light terms as a HID light, but may still be emitting light of strong density that can be used efficiently for photosynthesis (the absorption peaks of chlorophyll a and b are in the blue and red section of the electromagnetic spectrum) and plant growth. HID lights emit a larger amount of yellow and green light, colors that can be more easily seen by the visible eye, and as a result appear brighter.
Topics: Advice | Tags: higher wattage bulb, led grow light intensity, led grow light wattage | No Comments »