How to Choose Lighting for your Hydroponic Crop

Light (along with water) is the most important part of the life cycle of any plant. Deciding on the right amount of light, or the right kind of light, can sometimes be tricky. One of the most common problems faced by hydroponic growers is lack of light. You can buy the lights you need from any Oasis Garden shop, or on their website. Plants need a lot of light to grow. In the world of lamps, there are very powerful and expensive ones which consume large amounts of power. It’s definitely not the best option. The solution? Buying light emitting diode (LED) lamps to deal with a very efficient yet low consuming light source for your plants. 

Why are grow lamps so expensive and how are LEDS different? The traditional way of suppling artificial light to crops has been with the use of full spectrum lamps which can be either tungsten metal halide or high pressure sodium (although sodium lamps have a much narrower spectrum). These lamps are very inefficient – wasting most of the power given to them as heat – and therefore consume great amounts of power. A high pressure sodium lamp (HPS) needs to consume about 400-700W to be able to sustain an average tomato plant. The truth is that most of this energy is wasted as heat and almost none of it (around 20-40W of light) are actually absorbed by the plant.

With LEDs, the story is much different. Light emitting diodes are very efficient in generating light from electricity (wasting only a small amount of the energy as heat) and they also provide light in very narrow ranges which can be tuned to only supply the wavelengths needed by plants. Plants are green because their main photosensitive pigment is chlorophyll (there are several types by the way), a pigment that absorbs red and blue wavelengths and reflects green. With this in mind – not only are LEDS able to supply your hydroponic plants with a higher efficiency – but they are also able to provide your plant with only the colors of light it needs. Achieving a double gain in efficiency. As a matter of fact, a LED lamp with just 60W is enough to grow a tomato plant.

However, not all LEDS are created equal. Many people don’t know the difference between LEDs and end up buying cheap LED lamps or panels that simply do not provide plants with the energy they need to grow. There are generally two kinds of LEDS available for lamps. The first kind – low power LEDS – are the type of lights used to make your computer and keyboard lights. These lights are weak and they are usually sold in the forms of panels with HUNDREDS to make them appear “useful” for hydroponic growth. The second – high power LEDS – are lights used for traffic lights and high power applications and they ARE the type you need for hydroponic growth.

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In general, when you are looking to replace your TMH or HPS lamps with LEDs you need to look for high power LED lamps in the range of 50-100W for each 400W lamp you want to replace. You also need to look at the red to blue light ratio since different plant varieties need different proportions of light. If you are growing plants that need to have flowers then you will need to aim for a red to blue ratio of about 8:2 while plants that do not produce flowers may grow well with only red lights. There is obviously more to learn about light ratios for every type of plant, but you get the idea.



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