The lighting principle and technology of fluorescent lights?
Around 5 years ago, many cannabis growers used fluorescent lights to provide light energy to plants.
The light-emitting principle of fluorescent lights is to use electric current to emit ultraviolet light through mercury vapor, and then the ultraviolet light is absorbed by the phosphor in the tube. The photons with high energy are split into photons with low energy and then spread out. To put it simply, ultraviolet light illuminates the phosphor, and the phosphor shines.
Philips has made great improvements to the early fluorescent lights, allowing them to emit light of different spectra and greatly improving the luminous efficiency. The fluorescent lights we are using is based on the improvement of Philips technology.
The advantage of this technology is to make the spectrum richer and make the luminous efficiency high. But the disadvantage is that the phosphor and mercury vapor will be oxidized or leaked during the energy absorption process, causing small black spots inside the fluorescent lights which may also cause human mercury vapor poisoning. In order to prevent these situations from shortening the life of the lights or causing harm to people, the maximum power of the fluorescent lights generally produced does not exceed 150W watts.
The spectrum of the fluorescent lights is finalized when the manufacturer produces it. If you want to check whether the spectrum is suitable, you can read “Weed Grow Lesson 8: Configure cannabis grow lights”.
How to choose fluorescent lights for cannabis cultivation?
Choosing a fluorescent lights is mainly to choose the power, because to meet the minimum illumination of 2500 lumens, a larger power is required. In view of the rigid shortcomings of the fluorescent lights, we can only choose the combined fluorescent lights. At present, the luminous efficiency of fluorescent lights is about 60 lumens ~ 80 lumens per watt. In order to meet 2500 lumens, we need at least 35W ~ 45W watts of total power and a suitable spectrum of fluorescent lights, and can reach the light intensity suitable for plant growth and development, we need 350W ～1000W power fluorescent lights combination.
What are the types of fluorescent lights?
Fluorescent lights on the market can now be simply divided into two categories, bulb fluorescent lights and tube fluorescent lights.
Fluorescent light bulb
The power of this kind of lights is about 20W, and you can also buy about 100W. How to match it depends on the individual. It is recommended to make a square socket and plug these lights together. Considering the light attenuation, we need at least 3-4 A fluorescent lights of about 20W, this is only the minimum demand! In addition, consider the spectrum of fluorescent lights.
Fluorescent tube light
The power is the same as the bulb type, and the price is about the same, but the bulb is larger and the lighting range is wider. When superimposing light intensity, we can expand the distance appropriately.
What is the cost of growing fluorescent lights?
Now let’s calculate the cost of lighting. The price of a fluorescent lights is about 6USD. In order to satisfy the lighting of 2, 3 cannabis, we need at least 4 to 5 bulbs or about 3 tubes, which is about 60USD. Cannabis generally grows for about 60 days, 30 days 20 hours of light, 30 days 12 hours of light, about 1000 hours of light, lighting power 80W, which is 80 degrees of electricity, the electricity bill is calculated at 0.4USD, and the electricity bill is 32USD, so the minimum lighting cost is about 50USD. If you want to reach a suitable level, the electricity bill must be at least about 150 USD, and the total lighting cost is about 200 USD.
Low power consumption is the advantage of fluorescent lights, but it is also its disadvantage. Because the light intensity is too low, we use fluorescent lights to supplement energy, which can easily cause slow growth of plants and too little THC accumulated during flowering.
In addition, because the intensity of the fluorescent lights is too small, we must hang it very close to the plant. This will save us a lot of space, but it will also cause insufficient lighting in the lower part of the plant. But there is also a solution, using the “green sea” planting method to make hemp grow highly uniform stems and receive light energy evenly.
The above is the detailed explanation of the fluorescent lights. Regarding the accounting cost, this is only the minimum algorithm. It is suitable for growers who are small-scale, small in space, only plant once or twice, and not very demanding on results. Its advantages are that low power consumption does not attract attention, low heat does not cause fires, and low lighting costs. Don’t plan to use the method of superimposing light intensity to perfectly grow hemp. If you do a careful calculation, you will know that it is impossible.
However, fluorescent lighting is very suitable in some planting processes. It is when the plants are weak, such as the seedling stage, cutting rooting stage, pressing soil rooting stage, soft light can prevent excessive water evaporation or excessive energy damage to the roots of the plant. Therefore, fluorescent lights are widely used in the early stage of plant rooting, and veterans usually have several fluorescent lamps.
The recommended brands are German EHEIM and Philips. When buying, you need to pay attention to the lights with a complete set of lights holders.