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It is impossible to grow healthy seedlings without additional lighting. The daylight hours are short in February. If it is not extended, the planting material will turn out to be weak, elongated and with thin stems. However, not all lamps are able to benefit plants. The best option is LED light for seedlings do it yourself, emitting light spectra useful for development.
The need for additional lighting
It is possible to grow seedlings without additional lighting, but the question is what will come of it. To get a good harvest in the fall, plants must initially develop well. Lack of light inhibits the process of photosynthesis, cell and root development.
The benefits of LED lighting are clear:
- backlight prolongs short daylight hours;
- uniform scattering of light prevents seedlings from stretching and bending;
- LEDs emit the light spectrum required for plant development.
All crops grown by seedlings in early spring need additional illumination.
Influence of light spectra on plants
Before figuring out how to make LED lighting for seedlings, you need to understand its benefits. Many vegetable growers think, why invent something if you can just put a table lamp over the seedlings. The device will extend the daylight hours, but whether there will be any benefit from such a backlight is an important question.
Most lamps do not emit blue and red light spectrum. It is these two colors that have a positive effect on the development of seedlings. The rays of the blue spectrum stimulate cell growth, and at the same time slow down the process. The plant stem is not thin and elongated, but strong. The red spectrum is needed for hatching shoots. The rays accelerate seedling, stimulate the development of the root system and the setting of inflorescences.
Green, yellow and other spectra of light are not assimilated by seedlings, but even reflected from the foliage. However, these colors are also useful for plants. Sunlight has a full spectrum of colors and green vegetation develops best under it.
Any LED made lighting for seedlings do it yourself only partially replaces sunlight. Artificial lighting must be combined with natural light. It is better to grow seedlings on a windowsill, installing mirrored foil shields on the sides and on the opposite side of the window glass. Reflectors will evenly direct daylight to all plants.
When making LED lamps for seedlings with your own hands, it is important not to forget to equip them with matte diffusers. Long light rays emitted by LEDs are difficult for plants to perceive. Diffusers bring artificial lighting parameters closer to natural light.
The advantage of using LEDs
On forums LED light for seedlings do it yourself intensively discussed by gardeners because of the obvious advantages:
- You can collect LED lamps for seedlings with your own hands from individual bulbs. The combination of LEDs with different luminescence allows you to collect spectra useful for the plant in one light source.
- The high cost of high-quality LEDs pays off in energy savings.
- For the normal development of seedlings, illumination of 6 thousand lux is required, which is capable of providing a set of high-quality LEDs.
- Assembling a lamp from LEDs is no more difficult than soldering the ends of the wires.
A homemade or factory made LED fixture gives a lot of light, but does not emit heat. For seedlings, this factor is optimal. Even as close to the plants as possible, the LEDs will not burn the foliage.
Shelving unit with artificial lighting
Often do-it-yourself lighting of seedlings with LEDs on the shelves is installed. This is the most convenient construction for growing planting material. The rack allows you to place a large number of boxes in a small area.
For the manufacture of the structure, a wooden bar is used. You can use a metal corner, and even thin PVC sewer pipes. The shelves are cut from plywood or other durable material. The number of tiers depends on the installation location of the rack. It will be possible to build only three shelves on the windowsill, since it is necessary to maintain a minimum distance between them - 50 cm. A stationary rack for floor installation is made of 4–5 tiers.
LED lighting is located above each shelf. It is better to make lamps on suspensions. Any chain or rope will do. The wire from the lamps is fixed to the elements of the rack frame.
Assembling a homemade backlight
It is convenient to assemble a lamp from LEDs. Small bulbs can be positioned on the base as you like. Seedlings are usually grown on long shelves. In order for the luminaire to cover the entire area, the LEDs are arranged in two strips, alternating red and blue bulbs.
The distance between the LEDs depends on the emitted light cone. The lower the indicator, the closer to each other the bulbs are placed. Cone projections of light must overlap. The lamp must be made adjustable, since the seedlings at different times of growth are sensitive to certain spectra and light intensity.
From the moment of germination to picking, plants have a great need for the blue spectrum. The luminaire is made so that different groups of lamps can be switched on separately. During this growing period, blue and red LEDs should be lit in a 2: 1 ratio. The need for a blue glow is associated with the development of the stem. It does not stretch upwards, but thickens. At the same time, the development of the root system takes place.
Immediately after the pick, the brightness of the lighting is reduced for 2-3 days. After stress, seedlings need rest and recuperation. Further illumination during the month is carried out at normal brightness, only the ratio of red and blue LEDs is acceptable 1: 1.
For a homemade lamp, you will need LEDs:
- red glow with a wavelength of 660 Nm - 30 pieces;
- blue glow with a wavelength of 452 Nm - 20 pieces;
- white glow with a color temperature of 4300K - 10 pieces;
- pure white glow with a color temperature of 5300K - 10 pieces.
The use of white LEDs with different color temperatures is due to the correspondence of the spectrum, close to midday and morning sunlight. For the LEDs to work, you need to buy a driver.
For homemade backlighting, a case from the old one is ideal fluorescent lamp... First, remove the matte diffuser. It will come in handy for a new lamp. All filling is removed from the body. An aluminum strip is installed in its place, where the LEDs are fixed with hot glue. At an equal distance from the sides and center of the case, two fans are installed, taken from any power supplies or computer coolers.
The LEDs are soldered into a chain with a wire parallel to each other, not forgetting to observe the polarity. All groups of paws are connected to the drivers.From the fans, the wire is pulled to the power supply. If the circuit has been correctly soldered, after the voltage is applied, the lamps will light up. It remains to install a matte diffuser, fix the chain pendants to the body, and the lamp can be hung over the seedlings.
In order not to solder with each light bulb, it is easier to buy one blue and two red LED matrices, designed for 10 watts. A block with an output voltage of 24 volts and a current of 2 A is used for power. Computer coolers will serve as fans. To connect them, you will need a separate unit with an output voltage of 12 volts. An aluminum plate is suitable for dissipating heat from the matrices. The element needs to be anodized to avoid short circuits on the circuit.
The assembly of the luminaire begins with gluing the matrices with hot melt glue to the aluminum strip. The ends of the wires are tinned in solder with flux, after which they are soldered to the terminals of the matrices so that they connect plus and minus. The wires that go to the power supply are soldered to the terminals of the outer matrices. Fasteners for coolers are fitted on an aluminum plate and wires are pulled from them to another power supply. When the entire circuit is assembled, you can apply voltage and check the operation.
In the video, a do-it-yourself LED lamp for seedlings in the form of a profile lamp:
Determine the quality of homemade backlighting
You can visually determine whether LED lighting is beneficial to seedlings:
- thin elongated stems with thin leaves indicate a lack of light;
- even thick stems with wide succulent foliage indicate the correct brightness of the lamp.
The LEDs emit little heat, but the aluminum plate of the luminaire still heats up. To determine if the seedlings are too hot, the palms of the hands are placed over the plants. If you feel warm, then the lamp needs to be raised higher.
The seedlings themselves will let you know about the lack of light and the time the backlight is turned on in the evening. The leaves will begin to take on an upright position, trying to close together. It's easier to check the lack of light by turning on the lamp, even if it's daytime outside. If it becomes lighter over the seedlings, the lamp is left to work. The illumination brightness remains the same - no additional illumination is needed.
