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It is impossible to grow healthy seedlings without additional lighting. In February, daylight hours are short. If it is not extended, the planting material will turn out weak, elongated and with thin stems. However, not all lamps can benefit plants. The best option is LED lighting for seedlings with your own hands, emitting light spectra useful for development.
Need for additional lighting
It is possible to grow seedlings without additional lighting, but the question is what will come of it. In order to get a good harvest in the fall, the plants must initially develop well. Lack of light inhibits the process of photosynthesis, cell development and root system.
The benefits of LED lighting are obvious:
- lighting extends short daylight hours;
- uniform dispersion of light prevents seedlings from stretching and bending;
- LEDs emit the light spectrum necessary for plant development.
All crops grown as seedlings in early spring need additional lighting.
Effect of light spectra on plants
Before you figure 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 daylight hours, but whether such illumination will be beneficial is an important question.
Majority lamps do not emit blue and red light spectrum. It is these two colors that have a positive effect on the development of seedlings. Blue spectrum rays 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 by hatching sprouts. The rays accelerate seedlings, stimulate the development of the root system and the formation of inflorescences.
Green, yellow and other light spectra are not absorbed by seedlings, and are 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 with your own hands only partially replaces sunlight. Artificial lighting must be combined with natural light. It is better to grow seedlings on a windowsill, installing mirrored foil panels on the sides and on the opposite side of the window glass. Reflectors will direct daylight evenly to all plants.
When making LED lights for seedlings with your own hands, it is important not to forget to equip them with frosted diffusers. The long light rays emitted by LEDs are difficult for plants to perceive.Diffusers bring the parameters of artificial lighting closer to natural light.
Advantage of using LEDs
On the forums LED lighting for seedlings do-it-yourself is intensively discussed by gardeners because of its obvious advantages:
- You can assemble LED lamps for seedlings with your own hands from individual light bulbs. The combination of LEDs of different luminescence allows you to collect spectra useful for the plant in one light source.
- The high cost of high-quality LEDs is compensated by energy savings.
- For normal development of seedlings, an illumination of 6 thousand lux is required, which can be provided by 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 lamp produces a lot of light, but does not emit heat. This factor is optimal for seedlings. Even with maximum proximity to plants, LEDs will not leave burns on the foliage.
Shelving with artificial lighting
Often you install your own illumination of seedlings with LEDs on racks. This is the most convenient design for growing planting material. The rack allows you to place a large number of boxes in a small area.
Wooden beams are used to make the structure. You can use a metal corner, and even thin PVC sewer pipes. The shelves are cut out of 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 floor-mounted rack is made of 4-5 tiers.
LED lighting is located above each shelf. It is better to make lamps on pendants. Any chain or rope will do. The wire from the lamps is secured to the elements of the shelving frame.
Assembling a homemade backlight
It is convenient to assemble a lamp from LEDs. Small bulbs can be placed on the base as desired. Seedlings are usually grown on long shelves. To ensure that the lamp covers the entire area, the LEDs are arranged in two stripes, alternating red and blue bulbs.
The distance between LEDs depends on the emitted light cone. The lower the indicator, the closer the bulbs are placed to each other. The cone projections of light must overlap. The lamp must be made adjustable, since seedlings at different times of growth are sensitive to certain spectra and intensities of light.
From the moment of germination to picking, plants have a great need for the blue spectrum. The lamp is made in such a way that different groups of lamps can be switched on separately. During this growth period, blue and red LEDs should glow in a 2:1 ratio. The need for blue light is associated with stem development. It does not stretch upward, but thickens. At the same time, the development of the root system occurs.
Immediately after picking, the brightness of the lighting is reduced for 2-3 days. After stress, seedlings need peace and recuperation. Further illumination for a 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 light 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 matching spectrum, which is close to midday and morning sunlight. To operate the LEDs you will need to buy drivers.
For homemade lighting, a housing from an old one is ideal. fluorescent lamp. First remove the matte diffuser. It will be useful for a new lamp. All filling is removed from the body. In its place, an aluminum strip is installed, where the LEDs are fixed with hot glue. Two fans taken from any power supplies or computer coolers are installed at an equal distance from the sides and center of the case.
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 drivers. From the fans the wire is pulled to the power supply. If the circuit has been properly soldered, the lights will light up after voltage is applied. All that remains is to install the matte diffuser, attach the chain pendants to the body, and the lamp can be hung over the seedlings.
In order not to solder to each light bulb, it is easier to buy one blue and two red LED matrices rated at 10 W. For power supply, a unit with an output voltage of 24 volts and a current of 2 A is used. 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 removing heat from the matrices. The element needs to be anodized to avoid short circuits in the circuit.
Assembly of the lamp begins by gluing the matrices with hot glue to an aluminum strip. The ends of the wires are tinned in solder with flux, and then soldered to the terminals of the matrices to connect plus and minus. Wires going 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 its functionality.
The video shows a DIY LED lamp for seedlings in the form of a profile lamp:
Determining the quality of homemade lighting
You can visually determine whether LED lighting is beneficial to seedlings:
- thin elongated stems with thin leaves indicate a lack of light;
- smooth, thick stems with wide, succulent foliage indicate that the brightness of the lamp has been correctly selected.
LEDs emit little heat, but the aluminum plate of the lamp still heats up. To determine whether the seedlings are too hot, place the palms of your hands 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 when the lights are turned on in the evening. The leaves will begin to acquire a vertical position, trying to close together. It’s easier to check the lack of light by turning on the lamp, even if it’s day outside. If it becomes lighter above the seedlings, leave the lamp on. The brightness of the lighting remains the same - no additional lighting is needed.
