A series of articles about plant lighting from toptropicals.com

Part 1. Why light plants

Houseplants are very unlucky: they have to grow in a “cave,” and everyone knows that plants don’t grow in caves. The happiest plants get sunny windowsills, but such an arrangement in relation to the light is, rather, an analogue of the undergrowth under a tall tree, when the sun reaches only either in the early morning or in the evening, and even then it is diffused by the foliage of the tree.
Perhaps the most unique option for lighting plants was my previous home, when we lived separately on the eighteenth floor standing house. The windows were large (almost the entire wall), and no other houses or trees blocked them. My plants did not need lighting at all and managed to bloom 5-6 times a year (for example, bougainvilleas and callistemons). But, you know, this one is separate standing house- a rather rare phenomenon.
Usually plants in room conditions there is very little light (and not only in winter, but also in summer), and little light means no development, no growth, no flowering. This is where the question arises about additional illumination of plants in order to compensate for the lack of lighting in the conditions of the “cave” room.
Sometimes plants are grown completely without daylight - only with the help of lamps (for example: in a room where there are no windows; or if the plants are far from the window).
Before you start lighting plants, you need to decide whether you are going to illuminate them or fully illuminate them. If you only need to illuminate the plants, then in this situation you can get by with fairly cheap fluorescent lamps, almost without worrying about their spectrum.
The lamps are installed above the plants approximately 20 centimeters from the top leaf. In the future, it is necessary to provide for the possibility of moving them (lamps or plants). I usually placed the lights higher than expected and then "pulled" the plants up to the lights using pots turned upside down. Once the plants have grown, the pot-stand can be replaced with a smaller one or removed.
One more question: when you have already installed the lamps, how many hours a day should you add additional lighting? Tropical plants need 12-14 hours to fully develop daylight hours. Then they will develop well and bloom. This means you need to turn on the backlight a couple of hours before it gets light outside, and turn it off a few hours after it gets dark.
At full artificial lighting plants need to take into account the spectrum of lighting. Ordinary lamps are not enough here. If your plants do not see daylight, then you need to install lamps with a special spectrum for them - for plants and/or aquariums.
It is very convenient to use a relay timer when supplementary lighting or full illumination of plants. The most convenient way is to have a two-mode one, that is, the relay allows you to provide the plants with light both in the morning and in the evening.

Try giving plants extra light, and you will notice for yourself how much better they develop when they have enough light!

Galka Okhapkina

Part 2. Mysterious lumens and luxes.

In this part, we will very briefly talk about the basic concepts that those gardeners encounter who are trying to understand the huge variety of lamps for lighting plants.

Basic Concepts

Lumens and luxes are often confused. These quantities are units of measurement luminous flux and illumination that need to be distinguished.
The electrical power of a lamp is measured in watts, and light flow(“light power”) - in lumens (Lm). The more lumens, the more light the lamp produces. An analogy with a hose for watering plants - the more the tap is open, the “wetter” everything around will be.
Luminous flux characterizes the light source, and illumination- the surface on which light falls. By analogy with a hose, you need to know how much water gets to a particular point. This will determine how long you need to water the plants in the garden bed.
Illumination is measured in lux (Lx). A light source with a luminous flux of 1 Lm, uniformly illuminating a surface of 1 square meter, creates an illumination of 1 Lux on it.

Useful rules

Illumination on a surface is inversely proportional to the square of the distance from the lamp to the surface. If you move a lamp hanging above the plants at a height of half a meter to a height of one meter from the plants, thus doubling the distance between them, then the illumination of the plants will decrease by four times. This is something to keep in mind when you are designing a plant lighting system.
The illumination on a surface depends on the angle at which this surface is illuminated. For example: the sun on a summer afternoon, being high in the sky, creates illumination on the surface of the earth several times greater than the sun hanging low above the horizon on a winter day. If you use a floodlight type lamp to illuminate plants, try to ensure that the light is directed perpendicular to the plants.

Spectrum and color

The color of the lamp radiation is characterized color temperature (CCT - Correlated Color Temperature). This is based on the principle that if you heat up a piece of metal, for example, its color changes from red-orange to blue. The temperature of the heated metal at which its color is closest to the color of the lamp is called the color temperature of the lamp. It is measured in degrees Kelvin.
Another lamp parameter is color rendering coefficient(CRI - color rendering index). This parameter shows how close the colors of illuminated objects are to true colors. This value ranges from zero to one hundred. For example, sodium lamps have low color rendering: all objects under them appear to be the same color. New models of fluorescent lamps have a high CRI. Try to use bulbs with a high CRI value to make your plants look more attractive. These two parameters are usually indicated on the labeling of fluorescent lamps. For example, /735 - means a lamp with a value of CRI=70-75, CCT=3500K - a warm-white lamp, /960 - a lamp with CRI=90, CCT=6000K - a fluorescent lamp.

CCT(K)	Lamp	Color
2000	Sodium lamp low pressure(used for street lighting), CRI<10	Orange - sunrise-sunset
2500	Uncoated high pressure sodium lamp (HPS), CRI=20-25	Yellow
3000-3500	Incandescent lamp, CRI=100, CCT=3000K Warm-white fluorescent lamp, CRI=70-80 Halogen incandescent lamp, CRI=100, CCT=3500K	White
4000-4500	Cool-white fluorescent lamp, CRI=70-90 Metal halide lamp, CRI=70	Cool white
5000	Coated mercury lamp, CRI=30-50	Light blue - midday sky
6000-6500	Fluorescent fluorescent lamp (daylight), CRI=70-90 Metal-halide lamp (DRI), CRI=70 Mercury lamp (DRL) CRI=15	Sky on a cloudy day

As a result of the process of photosynthesis that occurs in plants, light energy is converted into energy used by the plant. During photosynthesis, a plant absorbs carbon dioxide and releases oxygen. Light is absorbed by various pigments in the plant, mainly chlorophyll. This pigment absorbs light in the blue and red parts of the spectrum. In addition to photosynthesis, there are other processes in plants that are influenced by light from different parts of the spectrum. By selecting the spectrum, alternating the duration of the light and dark periods, you can speed up or slow down the development of the plant, shorten the growing season, etc.
For example, pigments with a sensitivity peak in the red region of the spectrum are responsible for the development of the root system, fruit ripening, and flowering of plants. For this, greenhouses use sodium lamps, in which most of the radiation falls in the red region of the spectrum. Pigments with an absorption peak in the blue region are responsible for leaf development, plant growth, etc. Plants grown with insufficient blue light (for example, under an incandescent light bulb) are taller - they stretch upward to get more "blue light". The pigment that is responsible for the plant's orientation to light is also sensitive to blue rays.
This leads to an important conclusion: A lamp designed to illuminate plants must contain both red and blue colors.
Many fluorescent lamp manufacturers offer lamps with a spectrum optimized for plants. They are better for plants than regular fluorescent ones (used for indoor lighting). It makes sense to purchase such a lamp if you need to replace an old lamp: with the same power, a special lamp provides more “useful” light for plants. But if you're installing a new plant lighting system, don't bother with these specialized lamps, which are much more expensive than regular ones. Install a more powerful lamp with a high color rendering index (lamp marking - /9..). Its spectrum will contain all the necessary components, and it will provide much more light than a special lamp.

Absorption spectrum of chlorophyll (horizontal - wavelength in nm)

Udaff
www.TopTropicals.com

Part 3: lamps for plant lighting

This part will look at the types of lamps used to illuminate plants.
There are two types of lamps for lighting plants - incandescent lamps, which have a spiral, and gas-discharge lamps, where light is generated by an electrical discharge in a mixture of gases. Incandescent lamps can be plugged directly into an outlet. Gas discharge lamps require special ballasts (also called ballast ) - these lamps cannot be plugged into a power outlet

, despite the fact that some of them with their bases resemble incandescent lamps. Only new compact fluorescent lamps with built-in ballast can be screwed into the socket.
INCANDESCENT LAMPS

- These lamps, in addition to the usual incandescent lamps that are screwed into the chandelier on the ceiling, also include some other lamps: Halogen lamps

- , in which there is a mixture of gases inside the bulb, which increases the brightness and service life of the lamps. Do not confuse these lamps with discharge metal halide lamps, which are often called metal halide lamps. The new lamps use a mixture of krypton and xenon gases, due to which the brightness of the spiral glow is even higher. Neodymium lamps

, the flasks of which are made of glass with an admixture of neodymium (Chromalux Neodym, Eurostar Neodymium). This glass absorbs the yellow-green part of the spectrum, and illuminated objects appear visually brighter. In reality, the lamp produces no more light than a regular lamp. Incandescent lamps should not be used to illuminate plants.

They are not suitable for two reasons - there are no blue colors in their spectrum, and they have low light output (10-12 Lm/W). All incandescent lamps get very hot, so they should not be placed close to plants - otherwise the plants will get burned. And placing these lamps at a distance of more than one meter from the plants does practically nothing for them. Therefore, in indoor floriculture, such lamps are used exclusively for heating air in greenhouses and greenhouses. Another use of an incandescent lamp is in conjunction with a fluorescent lamp, which has little red light in its spectrum. For example, a combination of a cold light lamp and an incandescent lamp has a fairly good spectrum. However, it is better to use a sodium lamp instead of an incandescent lamp. Recently, special lamps for illuminating plants have appeared on sale, for example OSRAM Concentra Spot Natura with a built-in reflector. These lamps differ from ordinary ones in price (about 80-100 rubles in Moscow for a lamp with a power of 75-100 W). But the principle of operation, and, consequently, the efficiency of these lamps is the same as that of conventional incandescent lamps.
Lamps of this type are known to everyone - they are standard light sources in rooms. Fluorescent lamps are more suitable for illuminating plants than incandescent lamps. The advantages include high light output (50-70 Lm/W), low thermal radiation and long service life. The disadvantage of such lamps is that their spectrum is not entirely effective for illuminating plants. However, if there is enough light, then the spectrum is not so important. To operate these lamps, lamps with special ballasts (ballasts, ballast) are required. This equipment comes in two types - electromagnetic (electronic ballast - choke with starter) and electronic (electronic ballast, electronic ballast). The second is much better - the lamps do not flicker when turned on and in operation, the service life of the lamps and the amount of light emitted by the lamp increases. Some electronic ballasts allow you to adjust the brightness of the lamps, for example, from an external light sensor. There is only one problem: if the simplest choke costs about 200 rubles in Moscow, then prices for electronic ballasts start from 900 rubles, and adjustable electronic ballasts cost more than 2000 rubles without a regulating device, which costs another $70 to $90 (one such device can serve many lamps).
The power of the lamp depends on its length. Longer lamps provide more light. If possible, longer and more powerful lamps should be used, since they have a higher light output. In other words, 2 lamps of 36 W are better than 4 lamps of 18 W.
Lamps should be located no higher than half a meter from the plants. The optimal use of fluorescent lamps is shelves with plants of approximately the same height. Lamps are mounted at a distance of up to 15 cm for light-loving plants, and at a distance of 15-50 cm for those preferring partial shade. In this case, the lighting is mounted along the entire length of the shelf or rack.

SPECIAL PURPOSE FLUORESCENT LAMPS
These lamps differ from general purpose lamps only in the coating on the glass bulb. Due to this, the spectrum of these lamps is close to the spectrum required by plants. In Moscow you can find lamps from such manufacturers as OSRAM-Sylvania, Philips, GE, etc. Russian-made lamps with a spectrum optimized for plant illumination do not yet exist.
Prices for special lamps are at least twice as high as for general purpose lamps, but sometimes this is justified. As an example, here is the personal experience of one of the authors (A. Litovkin): “When the first winter crept up on my plants, I noticed that they began to, if not wither, then clearly stop developing. It was decided to illuminate them: a lamp with two lamps (1200 mm) was purchased. At first, domestically produced lamps with cold white light. The plants perked up noticeably, but they were in no hurry to start growing. Then (about a month) the general-purpose lamps were replaced with OSRAM Fluora and after that the plants, as they say, “fluttered.”
If you are installing a lamp instead of an old one, then it makes sense to use a specialized lamp for plants, since with the same power such a lamp provides more “useful” light for plants. But when installing a new system, it is better to install more powerful conventional lamps (high-power compact fluorescent lamps are best), since they provide more light, which is more important for plants than the spectrum.

COMPACT FLUORESCENT LAMPS

These lamps come with or without built-in ballast. In Moscow, lamps from the world's leading manufacturers and domestically produced lamps (MELZ) are presented, the characteristics of which are almost equal to their foreign counterparts, and at a significantly lower price.
Lamps with built-in ballast differ from extended general-purpose fluorescent lamps only in their smaller dimensions and ease of use - they can be screwed into a regular socket. Unfortunately, such lamps are produced to replace incandescent lamps for indoor lighting, and their spectrum is similar to that of incandescent lamps, which is not optimal for plants.
These lamps are best used to illuminate several compact plants. To obtain a normal light flux, the power of the lamps must be at least 20 W (analogous to 100 W for an incandescent lamp), and the distance to the plants must be no more than 30-40 centimeters.
Currently, high-power compact fluorescent lamps are on sale - from 36 to 55 W. These lamps are characterized by increased light output (20%-30%) compared to conventional fluorescent lamps, long service life, excellent color rendering (CRI>90) and a wide spectrum, which includes the red and blue colors necessary for plants. Compactness allows you to effectively use the lamps together with a reflector, which is important. These lamps are the optimal choice for lighting plants with low lighting system power (up to 200 W of total power). The disadvantage is the high cost and the need to use electronic ballast for high-power lamps.

GAS DISCHARGE LAMPS

Today, gas discharge lamps are the brightest light source. They are compact in size; Their high light output allows one lamp to illuminate plants that occupy a large area. Special ballasts must be used with these lamps. It should be noted that such lamps make sense to use if you need a lot of light; with a total power of less than 200-300 W, the best solution is to use compact fluorescent lamps.
Three types of lamps are used to illuminate plants: mercury lamps, sodium lamps and metal halide lamps, sometimes called metal halide lamps.

MERCURY VALVES

This is the most historically old type of all gas discharge lamps. There are uncoated lamps, which have a low color rendering index (everything appears dead blue under the light of these lamps), and newer lamps with a coating, which improves the spectral characteristics. The light output of these lamps is low. Some companies produce lamps for plants using mercury lamps, for example, OSRAM Floraset. If you are designing a new lighting system, it is best to avoid mercury lamps.

NHIGH PRESSURE ATRIUM LAMPS

This is one of the most efficient light sources in terms of light output. The spectrum of these lamps affects primarily plant pigments in the red zone of the spectrum, which are responsible for root formation and flowering. Of what is offered for sale, the most preferable are the Reflax lamps of Svetotekhnika LLC of the DnaT series (see photo). These lamps are made with a built-in reflector, can be used in lamps without protective glass (unlike other sodium lamps), and have a very significant resource (12-20 thousand hours). Sodium lamps provide a large amount of light, so a high-power ceiling lamp (250 W and above) can illuminate a large area at once - the best solution for illuminating winter gardens and large collections of plants. However, in such cases it is recommended to alternate them with mercury or metal halide lamps to balance the radiation spectrum.

METAL HALIDE LAMPS

These are the most advanced lamps for illuminating plants - high power, long service life, optimal radiation spectrum. Unfortunately, these lamps, especially those with an improved emission spectrum, are more expensive than other lamps. There are new lamps on sale with ceramic burners manufactured by Philips (CDM), OSRAM (HCI) with an increased color rendering index (CRI=80-95). The domestic industry produces lamps of the DRI series. The scope is the same as for high pressure sodium lamps.

Although the base of a metal halide lamp is similar to that of an incandescent lamp, it requires a special socket.

Afterword
Instead of an afterword - what will be useful and why.
*If you need to do something quickly and cheaply, then use incandescent lamps or a compact fluorescent lamp with a built-in ballast that can be screwed into a regular socket.
*Several closely spaced plants can be illuminated in different ways. A dozen small plants of approximately the same height (up to half a meter) are best illuminated with compact fluorescent lamps. For tall single plants, we can recommend floodlights with gas-discharge lamps with a power of up to 100 W.
*If plants of approximately the same height are located on shelves or on a windowsill, then use long fluorescent lamps or, even better, high-power compact lamps. Be sure to use reflectors with fluorescent lamps - they will significantly increase the useful luminous flux.
*If you have a large winter garden, then install ceiling lights with high-power discharge lamps (250 W and above).
Most of the lamps described can be purchased at electrical stores.

Summary table of lamps for plant lighting

	Incandescent lamp	Fluorescent Lamp	Compact fluorescent lamp	Gas discharge lamp
Lamp cost	Less than $5, $10-15 specialized	$5 - regular, $10-20 - specialized	$5 - low-power, for replacing incandescent lamps, $15-40 - lamps with a power of 35-90 W and specialized	Less than $20 - low-power lamp $30-80 - medium-power lamp, $50-150 - high-power lamps
Cost of ballast (ballast)		$5-10 - regular, $15-30 - electronic	Not needed for lamps that are screwed into a socket $20-30 - electronic, many high-power lamps work only with electronic	$20-50 - regular $30 -100 - electronic, which may include lamp adjustment, etc.
Cost of lighting system		<$10 - самодельный рефлектор с патронами $15-40 - система с лампами и балластом	<$20 - самодельная $30-100 - purchased	$100-500 - fully equipped system
Rated life	750 hours - lamp incandescent, More than 2000 hours. - halogen	15-20 thousand hours	15-20 thousand hours	5-20 thousand hours
Actual service life with daily illumination		6 months	9-12 months	One or two years
Heat generated	90 W at 1000 lm. Almost all of the lamp's energy is released as heat	Small 10-15 W per 1000 lm. Due to the fact that the lamp is long, the heat generated is not concentrated in one place. For a powerful system, using a small computer fan will solve the heating problem		Very little heat - 5-10 W per 1000 Lm, the heat is concentrated in one place. When using high-power lamps, a cooling system is required
Lighting system power range	It makes sense to use small lamps for illumination and heating	The plants are not very large. Groups of plants on a shelf or rack	Large groups of plants with a total system power of up to 200-300 W.	Large groups of plants and greenhouses - ceiling lighting

Part 4. Selecting a lighting system

In the three previous parts devoted to plant lighting, we talked about the basic concepts and different types of lamps. In this part we will talk about calculating lamp power, practical measurement of illumination and other important points related to this topic. You will learn which lighting system is best to choose for each specific situation, how many lamps are needed to illuminate a particular plant, how to measure illumination at home, why reflectors are needed in lighting systems.
Light is one of the most important factors for successful plant growth; they "make food" for themselves through photosynthesis. If the plant does not have enough light, then it is weakened and either dies from “hunger” or becomes easy prey for pests and diseases.

TO BE OR NOT TO BE?

So you've decided to install a new lighting system for your plants. First of all, answer two questions.
· What is your budget limit? If a small amount of money is allocated for the entire lighting system, which you “took” from the scholarship and you need to “meet” it, then this article will not help you. My only advice is to buy what you can. Don't waste your energy and time searching. Unfortunately, a lighting system for plants or an aquarium is not cheap. Sometimes a more reasonable alternative is to replace light-loving plants with shade-tolerant ones - it is better to have a well-groomed spathiphyllum that does not require a lot of light than to lament over a half-dead gardenia that is sorely lacking in it.
· Are you going to just hang around until spring, according to the principle “I don’t care if I’m alive”? Then just buy the simplest fluorescent lamp. If you want your plants to grow fully and even bloom under lamps, then you need to spend effort and money on a lighting system. Especially if you are growing plants that grow under artificial light all year round.
If you have decided on the answers to these questions and decided to install a full-fledged lighting system, then read on.

WHAT IS GOOD LIGHTING

Three main factors determine whether a lighting system is good or bad:
Light intensity. There should be enough light for the plants. Weak light cannot be replaced by long daylight hours. There is no such thing as too much light in indoor conditions. It is quite difficult to achieve the illumination that can occur on a bright sunny day (more than 100 thousand lux).
Duration of illumination. Different plants require different daylight hours. Many processes, such as flowering, are determined by the length of daylight hours (photoperiodism). Everyone has seen the red poinsettia (Euphorbia pulcherrima) sold at Christmas and New Year's. This bush grows under the window of our house in south Florida and every year in winter, without any tricks on our part, “does everything on its own” - our climate gives it what it needs to form red bracts - long dark nights and bright sunny days.
Lighting quality. In previous articles, I touched on this issue, saying that the plant needs light in both the red and blue regions of the spectrum. As already mentioned, it is not necessary to use special phytolamps - if you use modern lamps with a wide spectrum (for example, compact fluorescent or metal halide), then your spectrum will be “correct”.
In addition to these factors, others are certainly important. The intensity of photosynthesis is limited by what the plant lacks at the moment: in low light it is light, and when there is a lot of light, then, for example, temperature, or the concentration of carbon dioxide, etc. When growing aquarium plants, it often happens that when there is strong light, the concentration of carbon dioxide in the water becomes a limiting factor, and stronger light does not lead to an increase in the rate of photosynthesis.

HOW MUCH LIGHT DO PLANTS NEED?

According to light requirements, plants can be divided into several groups. The figures for each group are quite approximate, since many plants can feel good both in bright light and in the shade, adapting to the level of light. The same plant requires different amounts of light depending on whether it develops vegetatively, flowers or bears fruit. From an energy point of view, flowering is a process that wastes a large amount of energy. The plant needs to grow a flower and supply it with energy - despite the fact that the flower itself does not produce energy. And fruiting is an even more “wasteful” process. The more light, the more energy “from the light bulb” the plant can store for flowering, the more beautiful your hibiscus will be, the more flowers there will be on the jasmine bush.
Below are some plants that prefer certain light conditions; the level of illumination is expressed in lux (about lumens and lux it was already said earlier). Here I will only repeat that lux characterizes how “light” the plants are, and lumens characterize the lamps with which you illuminate these plants.

· Bright light. Plants that love bright light include those that naturally grow in open places (most trees, palm trees, succulents, bougainvillea, gardenia, hibiscus, ixora, jasmine, plumeria, thunbergia, crotons, roses, etc.). These plants prefer a high level of lighting - at least 15-20 thousand lux, and some plants require 50 thousand or more lux for successful flowering. Most variegated plants require high light levels - otherwise the leaves may “revert to a monochromatic color.”

Moderate light. Plants that love moderate light include “underbrush” plants (bromeliads, begonias, ficus, philodendron, caladium, chlorophytum, brugmansia, brunfelsia, clerodendrum, crossandra, medinilla, pandorea, rutia, barleria, tibuchina, etc.). The desired level of illumination for them is 10-20 thousand lux.

· Weak light. The concept of “shade-loving plants” is not entirely correct. All plants love light, including the dracaena standing in the darkest corner. It's just that some plants can grow (or rather exist) in low light. If you are not chasing the growth rate, they will do well in low light. Basically, these are plants of the lower tier (hamedorea, whitefeldia, anthurium, diefenbachia, philodendron, spathiphyllum, echinanthus, etc.). They need from 5 to 10 thousand lux.
The illumination levels given are approximate and can serve as a starting point for choosing a lighting system. Let me emphasize once again that these numbers are for the full growth and flowering of the plant, and not for “wintering”, when you can get by with a lower level of illumination.

ILLUMINANCE MEASUREMENT

So now you know how much light your plant needs and want to check if it's getting all it needs. All theoretical calculations are good, but it is better to measure the actual illumination where the plants stand. If you have a light meter, then you're in luck (pictured). If you don't have a light meter, don't despair. A camera's exposure meter is the same lux meter, but instead of illumination it displays shutter speed values, i.e. the time for which you need to open the camera shutter. The lower the illumination, the longer the time. It's simple.
If you have an external light meter, place it in the place where you are measuring illumination, so that the light sensor is perpendicular to the direction of the light falling on the surface.

If you are using a camera, place a sheet of white matte paper (see picture on the right) perpendicular to the direction of the incident light (do not use glossy paper - it will give incorrect results). Select the frame size so that the sheet fills the entire frame. There is no need to focus on it. Select a film speed of 100 (modern digital cameras allow you to “simulate” film speed). Determine the illumination using the shutter speed and aperture values. If you set the film sensitivity to 200 units, then the table values ​​must be halved; if the value is set to 50 units, then the values ​​are doubled. Moving to the next higher aperture number also doubles the values. In this way, you can roughly estimate the light level where your plants stand.

USING THE REFLECTOR

If you use a fluorescent lamp without a reflector, then you reduce the useful light several times. It’s easy to understand - only the light that is directed downwards hits the plants. Light that is directed upward is useless. The light that blinds your eyes when you look at an open lamp is also useless. A good reflector directs blinding light down onto the plants. The results of modeling a fluorescent lamp show that when using a reflector, the illumination in the center increases almost three times, and the light spot on the surface becomes more concentrated - the lamp illuminates the plants, and not everything around. Most lamps sold in household appliance stores do not have a reflector or have what is embarrassing to call a reflector. Special systems with reflectors for lighting plants or an aquarium are very expensive. On the other hand, making a reflector with your own hands is not difficult.

HOW TO MAKE A REFLECTOR FOR A FLUORESCENT LAMP

The shape of the reflector, especially one made for one or two lamps, is not of fundamental importance. Any “good” form of reflector, in which the number of reflections is no more than one and the return of light to the lamp is minimal, will have approximately the same efficiency within 10-15%. The figure shows a cross section of the reflector. It can be seen that its height should be such that all rays above the boundary one (ray 1 in the figure) are intercepted by the reflector - in this case, the lamp will not blind the eyes.
Having specified the direction of the reflected boundary ray (for example, downward or at an angle), you can construct a perpendicular to the reflector surface at the reflection point (point 1 in the figure), which divides the angle between the incident and reflected ray in half - the law of reflection. The perpendicular is determined in the same way at other points (point 2 in the figure).
To check, it is recommended to take a few more points so that you don’t get the situation shown at point 3, where the reflected beam does not go down. After this, you can either make a polygonal frame, or build a smooth curve and bend the reflector according to the template. The top point of the reflector should not be placed close to the lamp, since the rays will fall back into the lamp; the lamp will heat up.
The reflector can be made from aluminum foil (for example, food grade), which has a fairly high reflection. You can also paint the surface of the reflector with white paint. Moreover, its effectiveness will be almost the same as for a “mirror” reflector. Be sure to make holes on top of the reflector for ventilation.

DURATION AND QUALITY OF LIGHTING

The duration of illumination is usually 12-16 hours, depending on the type of plant. More accurate data, as well as recommendations on photoperiodism (for example, on how to make the poinsettia mentioned above bloom) can be found in specialized literature. For most plants, the above figure is quite enough.
The quality of lighting has already been discussed more than once. (photo from an old book) One of the illustrations can be a photograph of plants grown under lighting with a mercury lamp (there were practically no other lamps at that time) and an incandescent lamp. If you do not want long, skinny plants, do not use incandescent or sodium lamps without additional illumination with fluorescent or blue-emitting discharge lamps.
Among other things, the lamps should illuminate the plants so that they are pleasant to look at. A sodium lamp in this sense is not the best lamp for plants (the photo shows the difference - how plants look under a sodium lamp compared to lighting them with a metal halide lamp).

CALCULATION OF LAMP POWER

We have come to the most important thing - how many lamps to take to illuminate plants. Let's consider two lighting schemes: fluorescent lamps and a gas-discharge lamp.
The number of fluorescent lamps can be determined by knowing the average level of illumination on the surface. You need to find the luminous flux in lumens (multiplying the illuminance in lux by the surface area in meters). Light loss is approximately 30% for a lamp hanging at a height of 30 cm from the plants, and 50% for a lamp hanging at a distance of 60 cm from the plants. This is true if you use a reflector - without it, losses increase several times. Having determined the luminous flux of the lamps, you can find their total power, knowing that fluorescent lamps produce approximately 65 Lm per W of power.
For example, let's calculate how many lamps will be needed to illuminate a shelf with plants measuring 0.5x1 m. The area of ​​the illuminated surface will be 0.5x1=0.5 sq.m. Let's say that we need to illuminate plants that prefer moderate light (15,000 Lux). It will be difficult to illuminate the entire surface of the shelf with this level of illumination, so we will make an estimate based on the average illumination of 0.7x15000 = 11000 Lux. At the same time, we place plants that require more light on a shelf directly under the lamp, where the illumination is above average.
Total, you need 0.5x11000=5500 Lm. Lamps at a height of 30 cm should give approximately one and a half times more light (losses are 30%), i.e. about 8250 lm. The total power of the lamps should be about 8250/65=125 W, i.e. Two 55 W compact fluorescent lamps with a reflector will provide the required amount of light. If you want to install regular 40 W tubes, then you will need three or even four of them, since tubes placed close to each other begin to mutually shield, and the efficiency of the lighting system decreases. Try to use modern compact fluorescent lamps instead of conventional, mostly outdated, tubes.

If you do not use a reflector, then in this scheme you will have to take three or four times as many lamps.

Calculation of the number of fluorescent lamps

1. Select the light level.

2. Required luminous flux on the surface: L=0.7 x A x B (length and width in meters)

3. Required luminous flux of lamps taking into account losses (if there is a reflector): Lamp=L x C (C=1.5 for a lamp at a height of 30 cm and C=2 for a lamp at a height of 60 cm)

4.Total lamp power: Power=Lamp/65

For gas-discharge lamps the calculation is similar. A special luminaire with a 250 W sodium lamp provides an average illumination level of 15 thousand lux on an area of ​​1 sq.m.
If the lighting parameters of the lamp are known, then calculating the illumination is quite simple. For example, from the figure on the left you can see that the lamp (OSRAM Floraset, 80W) illuminates a circle with a diameter of about a meter at a distance of just under half a meter from the lamp. The maximum illumination value is 4600 Lux.
The figure on the right shows the luminous intensity curve (same light as above). To find the illumination at a distance from the lamp, you need to divide the luminous intensity by the square of the distance. For example, at a distance of half a meter under the lamp, the illumination value will be 750/(0.5x0.5)=3000 Lux.
A very important point when lighting plants is that the lamps should not overheat: as the temperature rises, their light output drops sharply. The reflector must have holes for cooling the lamps. If you use a lot of fluorescent lamps, you should use a fan to cool them (for example, a computer fan). High-power HID luminaires usually have a built-in fan.

Conclusion

In this series of articles, various issues of plant lighting were discussed. But many issues remained unaddressed, for example, the choice of the optimal electrical circuit for switching on the lamps, which is an important point. Those interested in this issue should better consult the literature or specialists.
The most rational scheme for designing a plant lighting system begins with determining the required level of illumination. Then you should estimate the number of lamps and their type. And only after that, rush to the store to buy lamps to illuminate your green pets.

Udaff, Andrey Litovkin
www.TopTropicals.com

The leaves of the plant are turning pale, your favorite flower has not thrown out its flower stalks for a long time, is the aquarium overgrown with algae? All these are signs that it’s time to go buy a special lamp for flowers.

You can find such lamps in almost any store. They come in different shapes, sizes, operating principles and power. But how to choose exactly what you need? This is exactly what will be discussed next.

1 Categories of lamps for indoor plants

Lamps for plants differ not only in power, operating principle and cost. Before going to the store, you need to clearly understand whether the lamp will be used for aesthetic purposes or to provide additional illumination for plants in the fall and winter.

The choice of lamp also depends on how sensitive the flora is to heat.

Based on their operating principle, light sources are divided into three categories:

• incandescent light bulbs;
• gas discharge;
• light-emitting diode lamps (LED).

1.1 Incandescent light bulbs

The most obvious way to add light is to place a regular table lamp next to the flowerpots. This solution is simple, but not aesthetically pleasing. In addition, a traditional light bulb generates heat and is difficult to place so that the plant's leaves are not damaged by the heat.

Incandescent light bulbs consume a lot of electricity with low light output, and their constant use will be expensive.

Moreover, the spectrum lacks the blue color necessary for indoor flora. That is, it is better to refuse to use traditional light bulbs.

1.2 Gas-discharge light sources

A gas-discharge type light bulb contains a bulb with a special gas.

Representatives of this category include metal halide, sodium, mercury and mercury-free lamps:

1. Metal halide. The discharge tube is filled with an inert gas (argon), mercury and radiating additives based on metal halides. The lamps are designated MGL on the packaging and have increased light output in the blue spectrum, which is good for seedlings. Metal halide bulbs activate vegetation, prevent excessive growth, stimulate the formation of internodes, bud formation and earlier flowering.
2. Sodium. They work in sodium vapor and produce a bright yellow or orange light. The most common representatives of this type are HPS lamps with a cylindrical bulb. There are low and high pressure lamps. The latter appeared later; high sodium vapor pressure improved color rendering, but the light output decreased. Sodium lamps are used for plants in greenhouses, and also when a powerful light source is needed.
3. IN mercury-free gas lamps The gas discharge tube is filled with inert gas. They are divided into xenon (daylight) and neon (orange).
4. Luminescent. The main feature is that the container with mercury and inert gas is coated with a phosphor on the inside. The lamp may look like a long, narrow tube. Compact ones are also available in the form of a white curved flask for a standard cartridge.

These lamps are used for illumination because they have high luminous efficiency. Another advantage is durability provided that it is turned on and off infrequently. The ESL (energy saving) designation on the packaging implies that the fluorescent light source is economical.

1.3 LED backlight

LEDs are used as a light source due to their economical energy consumption and durability. What other lighting system can operate up to 70 thousand hours? This service life is typical exclusively for LED lamps.

The LED (or LED) lighting mechanism makes it easy to obtain the desired spectral range without the use of filters. Diode lamps for plants do not contain mercury; the lamps can change the direction of radiation.

2 How to choose lamps for plants at home?

Completely different lamps are needed for greenhouses and for growing flowers at home on a windowsill. Special lamps are purchased for the plant inhabitants of the aquarium - they have specific requirements for the spectrum.

To see your home filled with flowering plants, you will need the following lamps:

1. Greenhouses and growboxes. In small grow rooms, plant growth can be stimulated using energy-saving ESL light bulbs. If the box occupies more than 0.5 sq. m, it is more advisable to use DNAT. In greenhouses, high-pressure sodium lamps have performed well for intensive growth, flowering and fruiting of crops. Such lamps make it possible to grow most plants all year round.
2. Plants in the apartment. Devices for illuminating flowers are selected depending on the height of the flowerpots. If there are several low plants on the windowsill, you can place powerful compact fluorescent lamps close to the flowerpot. If the width of the window sill or shelving allows, long fluorescent lamps for lighting plants will be appropriate. A tall, lonely ficus requires gas-discharge light bulbs with a power of up to 100 W. When you need not just decorative lighting, but light for plant growth, you should use fluorescent lamps with reflectors that increase the luminous flux. There are also special tubular fluorescent lamps for growing Fluora plants. They not only compensate plants for the lack of light, but also stimulate growth and other photobiological processes.
3. Aquarium. There are special requirements for a lamp for aquarium plants. It should not increase the water temperature. The lamp should be bright so that the plants grow, but not so powerful that it turns the aquarium into a lantern. In addition, the aquarium requires light of a certain spectrum so as not to provoke the appearance of a green coating on the walls. The indicated characteristics correspond to LED and fluorescent aquarium lamps. For the development of useful plants, it is better to illuminate the water with a powerful phytolamp for 8 hours than with a weak one for 16-20 hours. The phytolamp should not contradict the concept of the simulated body of water (blue light for sea water, white light for fresh water).
4. Winter Garden. You can organize lighting in a large winter garden yourself. Ceiling lamps with powerful gas-discharge phytolamps (more than 250 W) are suitable for illuminating flowers.

It’s easy to understand the variety of special lighting. The first step is to study the needs of the flower. The second stage is to choose an LED, fluorescent or MGL lamp. All that remains is to install the right lighting and enjoy the flowers in your home all year round.

Lamps for plants are an opportunity to compensate for the lack of light, which is especially important in the autumn-winter period. After all, even if you place the plants on the south side of the house (which is not always possible), the duration of natural daylight, especially in the northern regions, will be completely insufficient for the normal development of flowers or seedlings. For the full development of some plants, the duration of daylight hours must be at least 15 hours, otherwise the flowers begin to hurt - flowering stops, growth slows down, leaves wither and turn yellow, which can lead to their complete death. Phytolamps, an artificial sun substitute, prolong daylight hours and create optimal conditions for raising pets.

In industrial conditions, phytolamps often completely replace natural light - by adjusting the lighting mode (as well as adjusting climatic conditions), you can control the process of plant development and maturation as precisely as possible.

Light: how important is it for plants?

Light is an important component of plant life, because a plant (more precisely, its dry mass) consists of 45% carbon obtained from the air. At the same time, the process of carbon assimilation - photosynthesis, occurs only with the participation of light; the intensity of photosynthesis is influenced by many external factors, but the main one is still the intensity of light.

It is primarily young plants and shoots that suffer from a lack of light - their leaf blades become pale, desaturated, and their size becomes smaller. Their stem and internodes elongate, and the plant itself bends/stretches towards the light source. In addition, there are other signs (Fig. 1):

• plant growth slows down
• the formation of new buds stops, old flowers gradually die off, with a large deficiency of light, flowering may stop completely

• variegated species lose their decorative coloring and become monotonous green
• the lower leaves dry out and fall off

However, saying “light” is not entirely correct - flora perceives spectral components differently:

• red (wavelength from 600 to 720 nm) and orange (from 595 to 620 nm) are the most important and necessary radiation ranges for a plant; they supply the energy that is necessary for photosynthesis. In addition, they affect the speed of plant development, for example, an excess of orange and red rays allows you to delay the transition to flowering, which is important if, for example, you force bulbs to a certain date
• violet and blue (range 380-490 nm) - also directly involved in photosynthesis. They are needed, first of all, for the formation of protein, and also affect plant growth. Plants that naturally grow in short-day conditions bloom faster when grown at home precisely under the influence of the violet-blue part of the spectrum.
• ultraviolet rays (spectrum 315-380 nm) do not allow plants to “stretch”, and are so necessary for the synthesis of certain vitamins. Other rays in this range (wavelength 280-315 nm) help increase the cold resistance of plants
• green (490-565 nm) and yellow (565-595 nm) waves are not as important for plant development

That is why, when organizing additional lighting or artificial lighting of plants, it is necessary to take into account their needs only in a certain part of the spectrum.

Advice! In order not to disturb the “biological clock” of the plant, it is better to turn on artificial lighting at 7-8 o’clock in the morning, and turn it off, after maintaining the required duration of daylight, at 20-22 o’clock.

Lamps for plants: which ones to choose Where plants are located with insufficient or no natural light, you need to provide them with additional light from artificial sources

Incandescent lamps

Today it is an absolutely unacceptable option for illuminating plants. Firstly, their spectrum completely lacks blue spectrum waves, which are very important for the process of photosynthesis. Secondly, these lamps get very hot, so if placed close to plants, they can cause thermal burns on the leaf blades. Thirdly, lamps of this type have a very low (only about 5%) efficiency. And although the lamp itself is quite cheap, if used for a long time this will cause high electricity costs.

Many people know that in order for indoor plants to develop and bloom well and fully, they need to be provided with sufficient lighting. Thanks to sunlight, photosynthesis occurs, without which no plant can grow. In summer, plants receive light naturally, but in winter and cold weather, artificial supplementary lighting is required. There are special photo lamps for plants for these purposes. You can make them yourself, or you can buy them ready-made. Today we will tell you what they are and what reviews there are about them.

Advantages of using these devices

All indoor plants, depending on lighting requirements, are divided into the following categories:

• plants that need daytime sunlight;
• flowers that can develop in diffused light;
• specimens that can grow and develop in a dark place.

LED philolamps, depending on the indicators above, can have different wavelengths:

• 400 nm;

The advantages of using them for plants are:

• flowers are better able to absorb chlorophyll A, which is one of the key sources of their energy;
• thanks to the consumption of this component, the growth and development of the plant root system improves, and its metabolism accelerates;
• phytohormones are produced, thanks to which the protective properties of indoor plants and flowers are stimulated.

Key characteristics of phytolamps for plants

Reviews about this device are mostly positive; most indoor plant lovers note that the lamps help improve the physical properties of plants.

Phytolamps are energy-saving devices; they LED samples consume 10 times less energy than conventional lamps. This type of lamp can be used continuously for 500–100,000 hours. Its heating temperature can vary from 30 to 55 degrees, which is completely safe for plants.

On the market you can often find LED lamps that include both blue and red LEDs at the same time. This will save you the cost of purchasing two llamas of different colors separately. LEDs perform the following functions:

• The blue tint of the lamp stimulates plant growth;
• thanks to the red color, colorful flowering is ensured;
• the purple hue stimulates both.

Ready-made phytolamps can be purchased for every taste, You can always read reviews about manufacturers on the Internet.. In addition to LED lamps, there are other types of phytolamps on sale:

• sodium;
• luminescent;
• xenon;
• metal halide;
• neodymium;
• krypton.

It is worth noting that a phytolamp is not the cheapest device, regardless of its type. However, if you are growing indoor plants, you still need to have it.

Despite the diversity of species, The LED phytolamp is considered the best. Its advantages are:

• safety;
• efficiency;
• environmental friendliness.

All models of such lamps are compact and have an attractive design. The price of the finished product depends on the brand, model and configuration. If desired components can be purchased separately and assemble the phytolamp with your own hands. This will allow you to save your money.

What to consider before assembling the structure?

If you decide on the option of assembling a phytolamp yourself, then take into account the following nuances:

• In order for plants to be fully illuminated, the light must be not only blue, red and violet. For the full development and growth of crops, green and yellow LEDs will be required;
• During the day, the diode phytolamp should work no more than 14 hours. In winter, as in summer, flowers need a break from light exposure;
• to achieve the maximum effect of the lamp, you need to correctly select its distance to the plant;
• for diffuse lighting you need to use a matte screen. This type of lighting is best suited for many indoor flowers.

How to make a phytolamp with your own hands

In order for the design to be made with high quality and work correctly, you need to choose a spectrum taking into account the characteristics of indoor plants.

At the initial stage of their growth LEDs of exclusively red and blue colors are used. The growth and development of flowers largely depends on how they are located and their relationship with each other.

All diodes individually emit a cone-shaped light. And in order for the lighting under the device to be uniform, the cones must overlap each other. To grow a flower with a developed root system, you need to use a device with blue and red diodes in a ratio of 2 to 1. The result will be like this:

• developed root system;
• succulent leaves;
• thick stem.

When the plant grows, the proportions of red and blue diodes should be equal.

To assemble a phytolamp yourself, you need to prepare the following:

• old lampshade;
• diodes in the amount of 30 red pieces, 20 blue, 10 pieces for lighting at midday and 10 for morning lighting, respectively;
• led drive (2 pieces);
• driver equipped with PWM control;
• a circuit breaker that ensures the safety of the electricity supply.

Assembly methods

Offers to your attention two options for assembling a phytolamp at home. The first option is the following:

• weld yourself a stable frame of the structure, the width of which should correspond to the window sill;
• place the lampshade on the aluminum plate, having previously secured the diodes;
• The lamp must be placed so that it is as comfortable as possible for the flowers. The location can be adjusted later.

The second method of assembling a phytolamp for plants looks like this:

• prepare two 10-watt LED matrices blue and one red, a strip of anodized aluminum, two inverters, a cooler and an old lamp housing;
• Solder the wire to the matrices, taking into account its polarity. Connect the device with wires to the power supply;
• Secure the cooler and power supply with hot glue along with an aluminum strip. This will serve as a cooling system;
• for hot air to escape, you need to make two holes on the lamp body;
• Epoxy glue is used to firmly attach the diodes to the aluminum strip. The strip is bent into an arc to create a reflection effect, then everything is attached to the body.

Your phytolamp is ready and can be used according to application. If you properly care for it and use it carefully, it will last a very long time.

As was already said right away, LED lamps, ready-made or homemade, are the best option for lighting plants. They are economical and can work for a long time. They also create the most suitable conditions for growing plants.

But ordinary incandescent lamps cannot be used as phytolamps, since due to strong heating they can harm the flowers. Fluorescent induction phytolamps are a good option, but they have a significant drawback - a decrease in light intensity over time.

Rules for choosing a phytolamp

If you decide to purchase a ready-made phytolamp for your indoor plants, but are lost in the choice, consider the following tips on this matter:

• the selected device should not emit ultraviolet and infrared rays, which are dangerous for plants. This is especially true for flowers growing in greenhouses;
• When choosing a lamp for greenhouse conditions, consider the heating of the light sources. If the phytolamp is heated too much, the balance of temperature and humidity can be disrupted;
• lamps for seedlings should not affect the temperature balance, otherwise the young plant can be overdried or burned.

Phytolamps for plants: reviews

What do indoor plant lovers think about the use of phytolamps? Let’s read their reviews below.

I have quite a lot of experience in this area, more than 5 years. During this time, I used different types of lamps: incandescent lamps with different bases, and fluorescent lamps of different sizes. The height of the suspension should be determined by the tips of the leaves of your plants, but it should be at least 50 cm. For growing seedlings, I recommend fluorescent lamps; they need to be suspended at about 20 cm. All the benefits of using lamps are possible by adding neodymium and phosphor to the glass bulb. Due to all this, the plants feel comfortable, and the hard part of the radiation is suppressed.

Vladimir, Kyiv

At one time I didn’t use lamps at all when growing indoor plants. However, as an experiment, I decided to grow onions under a lamp for the New Year. I did this in a plastic container using the bridge method, and it turned out to be about 3 kilograms of greens. Of course, phytolamps are very expensive, but the result exceeds expectations.

Elena, Rostov-on-Don

I started using special phytolamps for growing greens in greenhouse conditions. At the same time, I tried different brands, some I liked more, some less, and in the end I settled on the option that I was completely satisfied with in terms of price and quality of work. Some people assemble them themselves and save even more, but I haven’t taken that risk yet. The harvest is good. I recommend everything for winter growing crops.

Alexey, Tver

It can be concluded that phytolamp for plants grown at home or in a greenhouse– an irreplaceable thing, thanks to which you can get a rich harvest of greenery or enjoy the flowering of your favorite crops, regardless of the time of year and solar activity.