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mogie
Well-Known Member
Found this:
There have been a lot of lighting questions lately so I thought I'd throw this out there.
Proper lighting may be the most important piece of the indoor garden. Photosynthesis and chlorophyll production occur throughout the spectrum with peaks in chlorophyll synthesis around 400nm in the violet wavelengths and photosynthesis around 700nm in the orange-red wavelengths. It's easy to see that any artificial light producing the visible spectrum can be used to grow plants. Only a few types of artificial lights will grow plants well.
Fluorescents and high intensity discharge (HID) lights have been the only useful artificials until the recent past when LED and MPS (microwave powered sulfur plasma) became available. The price of LED & MPS is still prohibitive for the grower on a small budget. Currently they are about twice the price of a dual 1000W system/bulbs/reflector/fans. However, LED's use much less energy and have a much longer life than HID and flourescents so their savings is realized slowly. MPS systems use 1000W of energy; they only offer savings in the less frequent bulb changes. MPS bulbs only need to be changed every 7 yrs while MH & HPS should be changed yearly.
Incandescent, halogen, and mercury vapor lights will grow plants, just not well. They produce a lot of heat and little light so they are much less efficient than the others. Their spectrums are heavily weighted on the red side which induces stretching (longer internode spacing). Heat also induces stretching which combined with the redder spectrum produces a spindly plant sparsely populated with leaves.
Lights are often rated in color temperature - degrees Kelvin (K). Low numbers indicate redder light while high numbers indicate bluer light; red light is designated warm and blue light is designated cool.
2100K - HPS
3000K - warm white
4200K - cool white, MH
5000K - "full spectrum"
6500K - "sunlight" or "daylight"
>9000K - specialty MH and fluoros
Fluorescents
Fluoros come in 2 types, standard tubes and compact fluorescents (CF or CFL). Tube fixtures house the ballasts that power the bulbs while CFL's can be screwed into any household socket. Conventional CFL's, that is. CFL's designed specifically for horticultural use often require a MOGUL socket. In both cases, the ballast is housed in the base of the bulb so they generate a bit more heat than tubes. The plants can't be quite as close. The biggest drawback with fluorescents is they only penetrate about 6". Blacklights produce uvA & uvB light and are useful as supplementals only. A better choice would be a 10,000K aquarium light. Fluoros designed specifically for horticultural use are available. Some employ targeted spectrum phosphors emitting a purple glow.
High Intensity Discharge (HID)
There are 3 varieties of HID lights useful for growing, HPS, MH, and MPS. HID lights require a ballast to provide the power to ignite them. Some have the ballast built into the fixture and others are available with a remote ballast. I recommend the remote ballast types for two reasons. First, the ballast is heavy and incorporating it into the fixture creates a very heavy fixture to hang over your delicate plants. Second, ballasts produce heat and being able to locate a remote ballast outside the growspace helps control heat. Electronic ballasts produce much less heat but are relatively expensive now. Horticultural lighting systems are available with shrouded cords. You simply hang the light and plug it in.
As the name implies, HID lights have a higher intensity and penetrate farther than fluoros.
50-70W penetrates about 1ft
150-250W penetrates about 1.5ft
400-600W penetrates about 3ft
1000W penetrates about 4ft
High Pressure Sodium (HPS)
HPS can be identified by the rosey glow it emits. Watt for watt, it produces more overall light than MH. HPS induces stretch (longer internode intervals) due to its redder light. It emits a spectrum useful for growing throughout the lifecycle although many growers use them only for flowering. Plain HPS bulbs work just fine, providing ample useable light for growth, but there are bulbs available with an enhanced blue spectrum to aid foliage growth and combat stretching. EYE Hortilux, Sunmaster, and Phillips Son Agro are 3 well known brands. Currently their cost is about 5 times that of a regular HPS bulb and worth it.
Metal Halide
MH emits a more natural white light. Watt for watt they emit less light than HPS (36,000 lumens for a 400W MH vs 50,000 lumens for a 400W HPS). Plants grow very compactly under the bluer light of MH, therefore many growers use them for vegetative growing and switch to HPS for flowering. Plants do very well under MH throughout their lifecycle, but the lack of red light inhibits flower/fruit production so the plants yield somewhat less. Sunmaster and others now make MH in enhanced spectrums as well; cool MH (4000-6000K) for vegging and warm MH (2000-3000K) for flowering. Light systems designed for aquariums are available with MH in the 9000K range. MH also produces a *small* amount of uvB light which is theorized to increase resin production and therefore increase potency.
LED
There are several websites to visit. LED Grow Lights.com offers proof that they work and excellent information on growing applications, with specific information on plants with low light requirements and those with high light requirements.
How much light do I need?
Cannabis is categorized as a high light plant. There are minimum levels of illumination required to insure compact plants. I have read that gardens can be successfully lit by as little as 2500 lumens/ft² when vegging and 5000 lumens/ft² when flowering. I have never used anything less than 3000 lumens/ft² for vegetative plants and 7500 lumens/ft² for flowering plants (in HID terms: 35W/ft² for veg and 60W/ft² to flower). Intensity degrades exponentially as you get farther from the source so the lights have to be kept close to the plants. To the indoor gardener that means less penetration through dense foliage. Ventilation is the key to keeping the light close. Air-cooled, tempered glass shielded hoods go a long way toward controlling heat. A small fan blowing right at the bulb works well also.
CaliGrower's Light Distance Charts for HID's are invaluable aids, displaying levels of illumination at specific distances as well as PAR energy. Photosynthetically Active Radiation (PAR) is how plants "see" light. There is a line on the chart indicating where various wattages provide equivalent PAR to the sun. As long as your light is that close, you will see lush, compact growth. Interestingly, Sunmaster is the only vendor I find that lists PAR wattages for their bulbs. This link is a FAQ with a more technical discussion of PAR as well as conversion factors for various lights.
Broadside Lighting
The angle of light is important as well. Rays of sunlight are almost parallel by the time they reach earth due to the distance between earth and sun. A 10ft plant is illuminated equally from top to bottom outdoors. That is not the case indoors where the plants are a few feet at most from the light. Hanging lights vertically without reflectors at varying heights between rows of plants insures illumination to the bottom of the plants, penetration to the center, and dense growth along their entire height.
There have been a lot of lighting questions lately so I thought I'd throw this out there.
Proper lighting may be the most important piece of the indoor garden. Photosynthesis and chlorophyll production occur throughout the spectrum with peaks in chlorophyll synthesis around 400nm in the violet wavelengths and photosynthesis around 700nm in the orange-red wavelengths. It's easy to see that any artificial light producing the visible spectrum can be used to grow plants. Only a few types of artificial lights will grow plants well.
Fluorescents and high intensity discharge (HID) lights have been the only useful artificials until the recent past when LED and MPS (microwave powered sulfur plasma) became available. The price of LED & MPS is still prohibitive for the grower on a small budget. Currently they are about twice the price of a dual 1000W system/bulbs/reflector/fans. However, LED's use much less energy and have a much longer life than HID and flourescents so their savings is realized slowly. MPS systems use 1000W of energy; they only offer savings in the less frequent bulb changes. MPS bulbs only need to be changed every 7 yrs while MH & HPS should be changed yearly.
Incandescent, halogen, and mercury vapor lights will grow plants, just not well. They produce a lot of heat and little light so they are much less efficient than the others. Their spectrums are heavily weighted on the red side which induces stretching (longer internode spacing). Heat also induces stretching which combined with the redder spectrum produces a spindly plant sparsely populated with leaves.
Lights are often rated in color temperature - degrees Kelvin (K). Low numbers indicate redder light while high numbers indicate bluer light; red light is designated warm and blue light is designated cool.
2100K - HPS
3000K - warm white
4200K - cool white, MH
5000K - "full spectrum"
6500K - "sunlight" or "daylight"
>9000K - specialty MH and fluoros
Fluorescents
Fluoros come in 2 types, standard tubes and compact fluorescents (CF or CFL). Tube fixtures house the ballasts that power the bulbs while CFL's can be screwed into any household socket. Conventional CFL's, that is. CFL's designed specifically for horticultural use often require a MOGUL socket. In both cases, the ballast is housed in the base of the bulb so they generate a bit more heat than tubes. The plants can't be quite as close. The biggest drawback with fluorescents is they only penetrate about 6". Blacklights produce uvA & uvB light and are useful as supplementals only. A better choice would be a 10,000K aquarium light. Fluoros designed specifically for horticultural use are available. Some employ targeted spectrum phosphors emitting a purple glow.
High Intensity Discharge (HID)
There are 3 varieties of HID lights useful for growing, HPS, MH, and MPS. HID lights require a ballast to provide the power to ignite them. Some have the ballast built into the fixture and others are available with a remote ballast. I recommend the remote ballast types for two reasons. First, the ballast is heavy and incorporating it into the fixture creates a very heavy fixture to hang over your delicate plants. Second, ballasts produce heat and being able to locate a remote ballast outside the growspace helps control heat. Electronic ballasts produce much less heat but are relatively expensive now. Horticultural lighting systems are available with shrouded cords. You simply hang the light and plug it in.
As the name implies, HID lights have a higher intensity and penetrate farther than fluoros.
50-70W penetrates about 1ft
150-250W penetrates about 1.5ft
400-600W penetrates about 3ft
1000W penetrates about 4ft
High Pressure Sodium (HPS)
HPS can be identified by the rosey glow it emits. Watt for watt, it produces more overall light than MH. HPS induces stretch (longer internode intervals) due to its redder light. It emits a spectrum useful for growing throughout the lifecycle although many growers use them only for flowering. Plain HPS bulbs work just fine, providing ample useable light for growth, but there are bulbs available with an enhanced blue spectrum to aid foliage growth and combat stretching. EYE Hortilux, Sunmaster, and Phillips Son Agro are 3 well known brands. Currently their cost is about 5 times that of a regular HPS bulb and worth it.
Metal Halide
MH emits a more natural white light. Watt for watt they emit less light than HPS (36,000 lumens for a 400W MH vs 50,000 lumens for a 400W HPS). Plants grow very compactly under the bluer light of MH, therefore many growers use them for vegetative growing and switch to HPS for flowering. Plants do very well under MH throughout their lifecycle, but the lack of red light inhibits flower/fruit production so the plants yield somewhat less. Sunmaster and others now make MH in enhanced spectrums as well; cool MH (4000-6000K) for vegging and warm MH (2000-3000K) for flowering. Light systems designed for aquariums are available with MH in the 9000K range. MH also produces a *small* amount of uvB light which is theorized to increase resin production and therefore increase potency.
LED
There are several websites to visit. LED Grow Lights.com offers proof that they work and excellent information on growing applications, with specific information on plants with low light requirements and those with high light requirements.
How much light do I need?
Cannabis is categorized as a high light plant. There are minimum levels of illumination required to insure compact plants. I have read that gardens can be successfully lit by as little as 2500 lumens/ft² when vegging and 5000 lumens/ft² when flowering. I have never used anything less than 3000 lumens/ft² for vegetative plants and 7500 lumens/ft² for flowering plants (in HID terms: 35W/ft² for veg and 60W/ft² to flower). Intensity degrades exponentially as you get farther from the source so the lights have to be kept close to the plants. To the indoor gardener that means less penetration through dense foliage. Ventilation is the key to keeping the light close. Air-cooled, tempered glass shielded hoods go a long way toward controlling heat. A small fan blowing right at the bulb works well also.
CaliGrower's Light Distance Charts for HID's are invaluable aids, displaying levels of illumination at specific distances as well as PAR energy. Photosynthetically Active Radiation (PAR) is how plants "see" light. There is a line on the chart indicating where various wattages provide equivalent PAR to the sun. As long as your light is that close, you will see lush, compact growth. Interestingly, Sunmaster is the only vendor I find that lists PAR wattages for their bulbs. This link is a FAQ with a more technical discussion of PAR as well as conversion factors for various lights.
Broadside Lighting
The angle of light is important as well. Rays of sunlight are almost parallel by the time they reach earth due to the distance between earth and sun. A 10ft plant is illuminated equally from top to bottom outdoors. That is not the case indoors where the plants are a few feet at most from the light. Hanging lights vertically without reflectors at varying heights between rows of plants insures illumination to the bottom of the plants, penetration to the center, and dense growth along their entire height.
mogie
Well-Known Member
Light for Plants
Without light, plants cannot grow. In the countries in which marijuana grows best, the sun is the source of light. The amount of light and the length of the growing season in these countries results in huge tree-like plants. In most parts of North America, however, the sun is not generally intense enough for long enough periods of time to produce the same size and quality of plants that grow with ease in Latin America and other tropical countries.
Sunshine is most intense at the equator where it is closest to the earth. Some of the largest, resin-coated buds in the world grow beneath this blazing sun. So what’s this got to do with indoor growing? Plenty. Light is one of the most basic needs of all plants and the most often mismanaged.
Even the most experienced growers forget about the basic needs of a plant, especially light.
The answer to the problem of lack of sun, especially in the winter months, shortness of the growing season, and other problems is to grow indoor under simulated conditions. The rule of thumb seems to be the more light, the better.
The common incandescent light bulb emits some of the frequencies of light the plant can use, but it also emits a high percentage of far red and infra-red light which cause the plant to concentrate its growth on the stem. This results in the plant stretching toward the light bulb until it becomes so tall and spindly that it just weakly topples over.
There are several brands of bulb type. One is the incandescent plant spot light which emits higher amounts of red and blue light than the common light bulb. It is an improvement, but has it drawbacks. it is hot, for example, and cannot be placed close to the plants.
Consequently, the plant has to stretch upwards again and is in danger of becoming elongated and falling over. The red bands of light seem to encourage stem growth which is not desirable in growing marijuana. The idea is to encourage foliage growth for obvious reasons.
Flourescent light tubes range in size from one to eight feet in length so you can set up a growing area almost anywhere. There are two types of flourescent lights; standard and the wide spectrum. They can be used in conjunction with one another, but the wide spectrum lights are not sufficient on their own. The wide spectrum lights were designed as a supplementary light source and are cheaper than the standard lights.
Wide spectrum lights emit the same bands of light as the standard but the standard emit higher concentrations of red and blue bands that the plants need to grow.
The wide spectrum lights also emit infra-red, the effect of which on stem growth we have already discussed. If you are planning to grow on a large scale, you might be interested to know that the regular flourescent lamps and fixtures, the type that are used in commercial lighting, work well when used along with the grow lights.
These commercial lights are called cool whites, and are the cheapest of the flourescent lights we have mentioned. They emit as much blue light as the standard grow lights and the blue light is what the plants use in foliage growth.
Intensity
Now we come to the question of intensity. Both the standard and wide spectrum lamps come in three intensities: regular output, high output, and very high output. You can grow a crop of plants under the regular output lamps. The difference in using the HO or VHO lamps is the time it takes to grow a crop.
Under a VHO lamp, the plants grow at a rate that is about three times the rate at which they grow under the standard lamps. People have been known to get a plant that is four feet tall in two months under one of these lights.
Under the VHO lights, one may have to raise the lights every day which means a growth rate of ate least two inches a day. The only drawback is the expense of the VHO lamps and fixtures. The VHO lamps and fixtures are almost twice the price of the standard.
Now that you have your lights up, you might be curious about the amount of light to give you plants per day. The maturation date of your plants is dependent on how much light they receive per day. The longer the dark period per day, the sooner the plant will bloom. Generally speaking, the less dark per day the better during the first six months of the plant's life.
If your plants receive 12 hours of light per day they will probably mature in 2 to 2.5 months. If they get 16 hours of light per day they will probably be blooming in 3.5 to 4 months. With 18 hours of light per day, they will flower in 4.5 to 5 months. Its a good idea to put your lights on a timer to ensure that the amount of light received each day remains constant.
Without light, plants cannot grow. In the countries in which marijuana grows best, the sun is the source of light. The amount of light and the length of the growing season in these countries results in huge tree-like plants. In most parts of North America, however, the sun is not generally intense enough for long enough periods of time to produce the same size and quality of plants that grow with ease in Latin America and other tropical countries.
Sunshine is most intense at the equator where it is closest to the earth. Some of the largest, resin-coated buds in the world grow beneath this blazing sun. So what’s this got to do with indoor growing? Plenty. Light is one of the most basic needs of all plants and the most often mismanaged.
Even the most experienced growers forget about the basic needs of a plant, especially light.
The answer to the problem of lack of sun, especially in the winter months, shortness of the growing season, and other problems is to grow indoor under simulated conditions. The rule of thumb seems to be the more light, the better.
The common incandescent light bulb emits some of the frequencies of light the plant can use, but it also emits a high percentage of far red and infra-red light which cause the plant to concentrate its growth on the stem. This results in the plant stretching toward the light bulb until it becomes so tall and spindly that it just weakly topples over.
There are several brands of bulb type. One is the incandescent plant spot light which emits higher amounts of red and blue light than the common light bulb. It is an improvement, but has it drawbacks. it is hot, for example, and cannot be placed close to the plants.
Consequently, the plant has to stretch upwards again and is in danger of becoming elongated and falling over. The red bands of light seem to encourage stem growth which is not desirable in growing marijuana. The idea is to encourage foliage growth for obvious reasons.
Flourescent light tubes range in size from one to eight feet in length so you can set up a growing area almost anywhere. There are two types of flourescent lights; standard and the wide spectrum. They can be used in conjunction with one another, but the wide spectrum lights are not sufficient on their own. The wide spectrum lights were designed as a supplementary light source and are cheaper than the standard lights.
Wide spectrum lights emit the same bands of light as the standard but the standard emit higher concentrations of red and blue bands that the plants need to grow.
The wide spectrum lights also emit infra-red, the effect of which on stem growth we have already discussed. If you are planning to grow on a large scale, you might be interested to know that the regular flourescent lamps and fixtures, the type that are used in commercial lighting, work well when used along with the grow lights.
These commercial lights are called cool whites, and are the cheapest of the flourescent lights we have mentioned. They emit as much blue light as the standard grow lights and the blue light is what the plants use in foliage growth.
Intensity
Now we come to the question of intensity. Both the standard and wide spectrum lamps come in three intensities: regular output, high output, and very high output. You can grow a crop of plants under the regular output lamps. The difference in using the HO or VHO lamps is the time it takes to grow a crop.
Under a VHO lamp, the plants grow at a rate that is about three times the rate at which they grow under the standard lamps. People have been known to get a plant that is four feet tall in two months under one of these lights.
Under the VHO lights, one may have to raise the lights every day which means a growth rate of ate least two inches a day. The only drawback is the expense of the VHO lamps and fixtures. The VHO lamps and fixtures are almost twice the price of the standard.
Now that you have your lights up, you might be curious about the amount of light to give you plants per day. The maturation date of your plants is dependent on how much light they receive per day. The longer the dark period per day, the sooner the plant will bloom. Generally speaking, the less dark per day the better during the first six months of the plant's life.
If your plants receive 12 hours of light per day they will probably mature in 2 to 2.5 months. If they get 16 hours of light per day they will probably be blooming in 3.5 to 4 months. With 18 hours of light per day, they will flower in 4.5 to 5 months. Its a good idea to put your lights on a timer to ensure that the amount of light received each day remains constant.
mogie
Well-Known Member
Energy Emissions In Arbitrary Color Bands
40 Watt Flourescent Lamps
In Watts and Percent of Total Emissions
Daylight Cool White Gro-Lux GroLux WS
Light Type Band Watts % Watts % Watts % Watts %
Ultra-Violet -380 0.186 2.15 0.16 1.68 0.10 1.42 0.27 3.16
Violet 380-430 0.832 9.60 0.72 7.57 0.70 9.67 1.07 12.48
Blue 430-490 2.418 27.91 1.98 20.78 1.96 27.07 1.22 14.29
Green 490-560 2.372 27.38 2.35 24.67 1.02 14.02 1.24 14.49
Yellow 560-590 1.259 14.53 1.74 18.27 0.10 1.42 0.83 9.77
Orange 590-630 1.144 13.21 1.69 17.75 0.44 6.05 1.36 15.93
Red 630-700 0.452 6.22 0.81 8.47 2.86 39.55 1.86 21.78
Far Red 700-780 0.130 1.53 0.07 0.81 0.06 0.80 0.69 8.10
Total 8.890 100.0 9.52 100.0 7.24 100.0 8.54 100.0
Grow Light Guide
Horticultural lighting systems allow you to extend the growing season by providing your plants with an indoor equivalent to sunlight. This is a great advantage for those of you who appreciate having a year-round supply of fresh flowers, veggies and herbs. Artificial lighting is also a great way to jump-start spring by starting your seedlings months ahead of the last frost. There are three main types of horticultural lighting systems.
In summary, marijuana has a lust for light. HP sodium lamps produce 20% more light than super metal halides. Horizontal reflectors yield up to 40% more light than vertical reflectors. Hammer or pebble specular, anodized aluminum or white are the most reflective surfaces for hoods. Mirror finish is the absolute worst reflective surface for a hood. Hang 400 watt lamps at 18-24” above garden, 600 and 1000 watt lamps, 24-30” above garden. Use a light meter. Grow the strongest, healthiest plants that reach their maximum potential for resin production. Bright light brings big buds.
HID (High Intensity Discharge) Lighting
HID lighting is the most efficient way to convert electricity into light that is available to the consumer. There are two types of HID grow lights used for horticultural lighting:
HID Light Efficiency
Metal Halide - MH
Metal halide bulbs produce an abundance of light in the blue spectrum. This color of light promotes plant growth and is excellent for green leafy growth and keeping plants compact. It is the best type of light to be used as a primary light source (if no or little natural sunlight is available). The average lifespan is about 10,000 cumulative hours. The bulb will light up beyond this time but due to the gradual decline of light, it is not worth your while to wait for the bulb to finally burn out. If you compare their lumen (brightness) per unit of energy consumed, metal halides produce up to 125 lumens per watt compared to 39 lumens per watt with fluorescent lights and 18 lumens per watt for standard incandescent bulbs.
40 Watt Flourescent Lamps
In Watts and Percent of Total Emissions
Daylight Cool White Gro-Lux GroLux WS
Light Type Band Watts % Watts % Watts % Watts %
Ultra-Violet -380 0.186 2.15 0.16 1.68 0.10 1.42 0.27 3.16
Violet 380-430 0.832 9.60 0.72 7.57 0.70 9.67 1.07 12.48
Blue 430-490 2.418 27.91 1.98 20.78 1.96 27.07 1.22 14.29
Green 490-560 2.372 27.38 2.35 24.67 1.02 14.02 1.24 14.49
Yellow 560-590 1.259 14.53 1.74 18.27 0.10 1.42 0.83 9.77
Orange 590-630 1.144 13.21 1.69 17.75 0.44 6.05 1.36 15.93
Red 630-700 0.452 6.22 0.81 8.47 2.86 39.55 1.86 21.78
Far Red 700-780 0.130 1.53 0.07 0.81 0.06 0.80 0.69 8.10
Total 8.890 100.0 9.52 100.0 7.24 100.0 8.54 100.0
Grow Light Guide
Horticultural lighting systems allow you to extend the growing season by providing your plants with an indoor equivalent to sunlight. This is a great advantage for those of you who appreciate having a year-round supply of fresh flowers, veggies and herbs. Artificial lighting is also a great way to jump-start spring by starting your seedlings months ahead of the last frost. There are three main types of horticultural lighting systems.
In summary, marijuana has a lust for light. HP sodium lamps produce 20% more light than super metal halides. Horizontal reflectors yield up to 40% more light than vertical reflectors. Hammer or pebble specular, anodized aluminum or white are the most reflective surfaces for hoods. Mirror finish is the absolute worst reflective surface for a hood. Hang 400 watt lamps at 18-24” above garden, 600 and 1000 watt lamps, 24-30” above garden. Use a light meter. Grow the strongest, healthiest plants that reach their maximum potential for resin production. Bright light brings big buds.
HID (High Intensity Discharge) Lighting
HID lighting is the most efficient way to convert electricity into light that is available to the consumer. There are two types of HID grow lights used for horticultural lighting:
HID Light Efficiency
Metal Halide - MH
Metal halide bulbs produce an abundance of light in the blue spectrum. This color of light promotes plant growth and is excellent for green leafy growth and keeping plants compact. It is the best type of light to be used as a primary light source (if no or little natural sunlight is available). The average lifespan is about 10,000 cumulative hours. The bulb will light up beyond this time but due to the gradual decline of light, it is not worth your while to wait for the bulb to finally burn out. If you compare their lumen (brightness) per unit of energy consumed, metal halides produce up to 125 lumens per watt compared to 39 lumens per watt with fluorescent lights and 18 lumens per watt for standard incandescent bulbs.
mogie
Well-Known Member
High Pressure Sodium - HPS
High pressure sodium bulbs emit an orange-red glow. This band of light triggers hormones in plants to increase flowering/budding in plants. They are the best lights available for secondary or supplemental lighting (used in conjunction with natural sunlight). This is ideal for greenhouse growing applications.
Not only is this a great flowering light, it has two features that make it a more economical choice. Their average lifespan is twice that of metal halides, but after 18,000 hours of use, they will start to draw more electricity than their rated watts while gradually producing less light. HPS bulbs are very efficient. They produce up to 140 lumens per watt. Their disadvantage is they are deficient in the blue spectrum.
If a gardener were to start a young plant under a HPS bulb, she/he would see impressive vertical growth. In fact, probably too impressive. Most plants would grow up thin and lanky and in no time you will have to prune your plant back before it grows into the light fixture. The exception to this is using a HPS light in a greenhouse. Sunlight is high in the blue spectrum which would offset any stretching caused by HPS bulbs.
Common manufacturers of metal halide and high pressure (HP) sodium lights include Philips, General Electric, Iwasaki, Venture, and Osram/Sylvania. Many of the manufacturers buy and use the same components, often manufactured by competitors. Most often the bulbs have the exact same technical statistics.
Lighting Chart - A guide for wattage per square foot.
HID Light Output Primary Growing Area Supplemental Area
100 watts 2' x 2' 3' x 3'
250 watts 3' x 3' 4' x 4'
400 watts 4' x 4' 6' x 6'
600 watts 6' x 6' 8' x 8'
1000 watts 8' x 8' 12' x 12'
HID Lighting Helpful Tips
Hanging height: Due to the heat that is emitted from these types of fixtures, you should hang them according to size. Smaller wattage systems (100 and 250) should be hung about 2 feet from the tops of the plants. Medium wattage systems (400 and 600) should be hung around 3 feet from the top of the plants. High wattage systems (1000 and up) should be placed at least 4 to 5 feet from the plant tops.
How long should lights run?
This depends on the type of plant. Most plants and vegetables need about 10 to 12 hours of light to promote growth. Plants that produce fruits or flowers will show improvement with up to 16 hours a day of supplemental light.
Fluorescent Lighting
This type of light is perfect for starts and seedlings. They are also popular for growing low-light plants like herbs and African violets. Fluorescent lights are low intensity and need to be placed within 8" (up to 15" for shade loving plants) of the plants to be effective. They are a poor light source for flowering and budding primarily because of their low lumen output.
Incandescent Lighting
These lights are also good for starts and seedlings and provide an inexpensive alternative to HID lights, because they do not require a ballast. These lights are only good for individual plants or small groups of plants because of their low lumen output and limited range.
The Cost to Run a Lighting System
To get the operating cost per hour for a light, take the lights combined wattage, and divide it by 1000 to get the kilowatts used. Then multiply that number by the amount your electric company charges per kilowatt hour. HID lights will use the number of watts it emits per hour, ie; 600w system will use 600 watts per hour (regardless of spectrum).
High pressure sodium bulbs emit an orange-red glow. This band of light triggers hormones in plants to increase flowering/budding in plants. They are the best lights available for secondary or supplemental lighting (used in conjunction with natural sunlight). This is ideal for greenhouse growing applications.
Not only is this a great flowering light, it has two features that make it a more economical choice. Their average lifespan is twice that of metal halides, but after 18,000 hours of use, they will start to draw more electricity than their rated watts while gradually producing less light. HPS bulbs are very efficient. They produce up to 140 lumens per watt. Their disadvantage is they are deficient in the blue spectrum.
If a gardener were to start a young plant under a HPS bulb, she/he would see impressive vertical growth. In fact, probably too impressive. Most plants would grow up thin and lanky and in no time you will have to prune your plant back before it grows into the light fixture. The exception to this is using a HPS light in a greenhouse. Sunlight is high in the blue spectrum which would offset any stretching caused by HPS bulbs.
Common manufacturers of metal halide and high pressure (HP) sodium lights include Philips, General Electric, Iwasaki, Venture, and Osram/Sylvania. Many of the manufacturers buy and use the same components, often manufactured by competitors. Most often the bulbs have the exact same technical statistics.
Lighting Chart - A guide for wattage per square foot.
HID Light Output Primary Growing Area Supplemental Area
100 watts 2' x 2' 3' x 3'
250 watts 3' x 3' 4' x 4'
400 watts 4' x 4' 6' x 6'
600 watts 6' x 6' 8' x 8'
1000 watts 8' x 8' 12' x 12'
HID Lighting Helpful Tips
Hanging height: Due to the heat that is emitted from these types of fixtures, you should hang them according to size. Smaller wattage systems (100 and 250) should be hung about 2 feet from the tops of the plants. Medium wattage systems (400 and 600) should be hung around 3 feet from the top of the plants. High wattage systems (1000 and up) should be placed at least 4 to 5 feet from the plant tops.
How long should lights run?
This depends on the type of plant. Most plants and vegetables need about 10 to 12 hours of light to promote growth. Plants that produce fruits or flowers will show improvement with up to 16 hours a day of supplemental light.
Fluorescent Lighting
This type of light is perfect for starts and seedlings. They are also popular for growing low-light plants like herbs and African violets. Fluorescent lights are low intensity and need to be placed within 8" (up to 15" for shade loving plants) of the plants to be effective. They are a poor light source for flowering and budding primarily because of their low lumen output.
Incandescent Lighting
These lights are also good for starts and seedlings and provide an inexpensive alternative to HID lights, because they do not require a ballast. These lights are only good for individual plants or small groups of plants because of their low lumen output and limited range.
The Cost to Run a Lighting System
To get the operating cost per hour for a light, take the lights combined wattage, and divide it by 1000 to get the kilowatts used. Then multiply that number by the amount your electric company charges per kilowatt hour. HID lights will use the number of watts it emits per hour, ie; 600w system will use 600 watts per hour (regardless of spectrum).
mogie
Well-Known Member
How the Sunlight Effects Plant Growth
200 - 280 nm UVC ultraviolet range which is extremely harmful to plants because it is highly toxic.
280 - 315 nm Includes harmful UVB ultraviolet light which causes plants colors to fade.
315 - 380 nm Range of UVA ultraviolet light which is neither harmful nor beneficial to plant growth.
380 - 400 nm Start of visible light spectrum. Process of chlorophyll absorption begins. UV protected plastics ideally block out any light below this range.
400 - 520 nm This range includes violet, blue, and green bands. Peak absorption by chlorophyll occurs, and a strong influence on photosynthesis. (promotes vegetative growth)
520 - 610 nm This range includes the green, yellow, and orange bands and has less absorption by pigments.
610 - 720 nm This is the red band. Large amount of absorption by chlorophyll occurs, and most significant influence on photosynthesis. (promotes flowering and budding)
720 - 1000 nm There is little absorption by chlorophyll here. Flowering and germination is influenced. At the high end of the band is infrared, which is heat.
1000+ nm
WHAT TYPE OF GROW LIGHT SHOULD I USE?
Full Spectrum Fluorescents are ideal for starting seeds or cuttings or for low light plants. They are the most energy efficient grow lights available.
Although more efficient than incandescent lights, fluorescents are still much less efficient than High Intensity Discharge (HID) light systems. Larger wattage systems will cover larger areas, and since these bulbs produce greater light intensity they are superior for growing taller plants.
Metal Halide (MH) and High Pressure Sodium (HPS) are the most common HID grow lights. MH bulbs emit a blue-white spectrum, which is more conductive for vegetative growth or starting seeds and clones. HPS bulbs are red-orange in the spectrum, which is ideal for the fruiting and flowering stage of a plant’s development.
200 - 280 nm UVC ultraviolet range which is extremely harmful to plants because it is highly toxic.
280 - 315 nm Includes harmful UVB ultraviolet light which causes plants colors to fade.
315 - 380 nm Range of UVA ultraviolet light which is neither harmful nor beneficial to plant growth.
380 - 400 nm Start of visible light spectrum. Process of chlorophyll absorption begins. UV protected plastics ideally block out any light below this range.
400 - 520 nm This range includes violet, blue, and green bands. Peak absorption by chlorophyll occurs, and a strong influence on photosynthesis. (promotes vegetative growth)
520 - 610 nm This range includes the green, yellow, and orange bands and has less absorption by pigments.
610 - 720 nm This is the red band. Large amount of absorption by chlorophyll occurs, and most significant influence on photosynthesis. (promotes flowering and budding)
720 - 1000 nm There is little absorption by chlorophyll here. Flowering and germination is influenced. At the high end of the band is infrared, which is heat.
1000+ nm
WHAT TYPE OF GROW LIGHT SHOULD I USE?
Full Spectrum Fluorescents are ideal for starting seeds or cuttings or for low light plants. They are the most energy efficient grow lights available.
Although more efficient than incandescent lights, fluorescents are still much less efficient than High Intensity Discharge (HID) light systems. Larger wattage systems will cover larger areas, and since these bulbs produce greater light intensity they are superior for growing taller plants.
Metal Halide (MH) and High Pressure Sodium (HPS) are the most common HID grow lights. MH bulbs emit a blue-white spectrum, which is more conductive for vegetative growth or starting seeds and clones. HPS bulbs are red-orange in the spectrum, which is ideal for the fruiting and flowering stage of a plant’s development.
mogie
Well-Known Member
Marijuana Lighting Tips
Although natural sunlight is the best form of light for growing plants, their life cycle can be controlled more effectively with artificial lighting
The life cycle of the Cannabis plant is determined by the daily photoperiod (hours of light per day).
A young marijuana plant tends to grow faster if it is grown under continuous light for the first two months of it's development.
Although the lamps should be kept as close as possible to the growing leaves, they should never be allowed to touch the plants.
The best light for plant growth emits high intensities of the blue and red bands of the light spectrum.
Fluorescent light is one of the most effective source of artificial light readily available to home growers.
Metal Halide lamps are better than most fluorescents, because they radiate more light in the blue and white bands of the light spectrum.
If your lights are too hot to touch with your hand, they are probably also too hot to be close to the growing leaves of plants.
The amount of light you supply your plants depends on the size of the garden, but at least 20 watts per square foot is recommended.
Although Metal Halide lamps are generally considered a better light source for marijuana growth, they use a lot more electricity than fluorescents..
Under artificial light, a marijuana plant can grow from three to six feet tall in three to four months.
Plants entering the vegetative stage enjoy up to twenty two hours of light per day, while twelve hours or less is required for flowering.
The more light you give your plants, the faster they will grow.
Lamps should be fixed to the roof in such a way that they can easily be raised as the plant grows in height.
The use of reflectors ensures that the light is spread more uniformly around the plants.
To increase the humidity of the air in a small, enclosed garden, place a small bowl of water in the grow room.
Use a fan to cool down your plants if the lights in a small grow room raise the temperature too much.
Plants grown in conditions of varying daily light patterns will not settle into a regular life cycle and will grow poorly.
If there is insufficient light in the grow room, the plants will often grow tall and thin, in search of the light.
Do not "wake up" your plants by switching on the lights if they are in the dark period of their daily light cycle.
Plants grown with a long daily photoperiod, will require more frequent watering than those grown with less light.
Although incandescent, or screw-in light-bulbs are usually not suitable for good growth, they can be used in conjunction with fluorescent tubes.
If the edges of the leaves near the lights and growing tips start curling up, it usually means that they are getting too hot.
A Cannabis plant will grow with as little as six hours of light per day, but requires more than twelve hours per day for good strong growth.
A plant grown with insufficient light may sometimes develop disfigured leaves with only one or two blades per leaf.
Paint the walls, floor and roof of your grow room white for better reflection of light onto your growing plants.
If you have a few plants growing unevenly under one light, you could raise the pots of the smallest plants by placing them on a few bricks.
Although easy to control, the daily light photoperiod is the single most important factor influencing the growth of your plants.
Cannabis plants require less than twelve hours of light per day for at least two weeks before you can expect to see the first signs of flowers appearing.
Never increase the daily light photoperiod to more than twelve hours, once your plants have started flowering.
A marijuana plant grown indoors with lots of light will often grow larger and more potent than a similar plant growing outdoors in natural light.
To increase the amount of light available to the lower branches, you could mount extra fluorescent tubes vertically, onto the walls of your grow room.
Although natural sunlight is the best form of light for growing plants, their life cycle can be controlled more effectively with artificial lighting
The life cycle of the Cannabis plant is determined by the daily photoperiod (hours of light per day).
A young marijuana plant tends to grow faster if it is grown under continuous light for the first two months of it's development.
Although the lamps should be kept as close as possible to the growing leaves, they should never be allowed to touch the plants.
The best light for plant growth emits high intensities of the blue and red bands of the light spectrum.
Fluorescent light is one of the most effective source of artificial light readily available to home growers.
Metal Halide lamps are better than most fluorescents, because they radiate more light in the blue and white bands of the light spectrum.
If your lights are too hot to touch with your hand, they are probably also too hot to be close to the growing leaves of plants.
The amount of light you supply your plants depends on the size of the garden, but at least 20 watts per square foot is recommended.
Although Metal Halide lamps are generally considered a better light source for marijuana growth, they use a lot more electricity than fluorescents..
Under artificial light, a marijuana plant can grow from three to six feet tall in three to four months.
Plants entering the vegetative stage enjoy up to twenty two hours of light per day, while twelve hours or less is required for flowering.
The more light you give your plants, the faster they will grow.
Lamps should be fixed to the roof in such a way that they can easily be raised as the plant grows in height.
The use of reflectors ensures that the light is spread more uniformly around the plants.
To increase the humidity of the air in a small, enclosed garden, place a small bowl of water in the grow room.
Use a fan to cool down your plants if the lights in a small grow room raise the temperature too much.
Plants grown in conditions of varying daily light patterns will not settle into a regular life cycle and will grow poorly.
If there is insufficient light in the grow room, the plants will often grow tall and thin, in search of the light.
Do not "wake up" your plants by switching on the lights if they are in the dark period of their daily light cycle.
Plants grown with a long daily photoperiod, will require more frequent watering than those grown with less light.
Although incandescent, or screw-in light-bulbs are usually not suitable for good growth, they can be used in conjunction with fluorescent tubes.
If the edges of the leaves near the lights and growing tips start curling up, it usually means that they are getting too hot.
A Cannabis plant will grow with as little as six hours of light per day, but requires more than twelve hours per day for good strong growth.
A plant grown with insufficient light may sometimes develop disfigured leaves with only one or two blades per leaf.
Paint the walls, floor and roof of your grow room white for better reflection of light onto your growing plants.
If you have a few plants growing unevenly under one light, you could raise the pots of the smallest plants by placing them on a few bricks.
Although easy to control, the daily light photoperiod is the single most important factor influencing the growth of your plants.
Cannabis plants require less than twelve hours of light per day for at least two weeks before you can expect to see the first signs of flowers appearing.
Never increase the daily light photoperiod to more than twelve hours, once your plants have started flowering.
A marijuana plant grown indoors with lots of light will often grow larger and more potent than a similar plant growing outdoors in natural light.
To increase the amount of light available to the lower branches, you could mount extra fluorescent tubes vertically, onto the walls of your grow room.
mogie
Well-Known Member
Hi there... I am mogie's hubby. She asked me to check out the Grow FAQ's. So I clicked on the link and my eye was running all over the page looking for them.
I saw this thing on the left that looked like a list of directories and sub-directories on my hard-drive. Some of the line were even cut off like there was more to read but they disappeared into what looked like some numbered folders.
Then my eye ran down a list that seemed totally foreign to everything else and certainly not FAQ's... it was under the heading of "Resent Articles" or some such BS. By this time I was getting really confused. I turned to her and said, "Where are the frequently asked questions?"
I looked back at the screen and saw a heading... "Categories".... Categories!!???.... categories for what??? I'm thinking... are these the frequently asked questions? So I began to read the names to see if any of it made any sense.
I don't mean to be rude, but... this page is a cluster-fuck. I know there is some good content in there because I watched my wife spend countless hours a day for weeks puting shit in there.
You guy's don't quite understand what FAQ's are supposed to do. There should be no more than six to a dozen questions on one page... and that's it... short simple easy for the eye to see and the newbie to understand.
I understand the heading is "Grow FAQ's." Well there is a big problem with this concept. Growing is complex... and FAQ's by internet standard are simplistic. Perhaps you need to rethink the structure of what it is you are trying to accomplish.
If a person post a question in a forum asking, "What kind of bug is this I found on my plant?" Is this a frequently asked question? No... but you guys will then try and put a whole article into FAQ's with pictures to try to cover the most common pests one might find on their plant. hmmmmm
Why don't you guys just write a book. That is what you are trying to do.
Actually, the articles in FAQ's are really good stuff... good information. Create a separate section for all the good stuff and call it "Rollitup's Tutorials," or something like that.
Don't have a "Grow FAQ" link... just have a FAQ link... and put about ten questions in it like... "How do I add pictures to my posts?" or "How do I delete my post?" or "What is rep and how do I get it?"....
Number one rule in all of this is... I hate to say it... "KISS" Keep it simple stupid.
Hope this is of some use.
I saw this thing on the left that looked like a list of directories and sub-directories on my hard-drive. Some of the line were even cut off like there was more to read but they disappeared into what looked like some numbered folders.
Then my eye ran down a list that seemed totally foreign to everything else and certainly not FAQ's... it was under the heading of "Resent Articles" or some such BS. By this time I was getting really confused. I turned to her and said, "Where are the frequently asked questions?"
I looked back at the screen and saw a heading... "Categories".... Categories!!???.... categories for what??? I'm thinking... are these the frequently asked questions? So I began to read the names to see if any of it made any sense.
I don't mean to be rude, but... this page is a cluster-fuck. I know there is some good content in there because I watched my wife spend countless hours a day for weeks puting shit in there.
You guy's don't quite understand what FAQ's are supposed to do. There should be no more than six to a dozen questions on one page... and that's it... short simple easy for the eye to see and the newbie to understand.
I understand the heading is "Grow FAQ's." Well there is a big problem with this concept. Growing is complex... and FAQ's by internet standard are simplistic. Perhaps you need to rethink the structure of what it is you are trying to accomplish.
If a person post a question in a forum asking, "What kind of bug is this I found on my plant?" Is this a frequently asked question? No... but you guys will then try and put a whole article into FAQ's with pictures to try to cover the most common pests one might find on their plant. hmmmmm
Why don't you guys just write a book. That is what you are trying to do.
Actually, the articles in FAQ's are really good stuff... good information. Create a separate section for all the good stuff and call it "Rollitup's Tutorials," or something like that.
Don't have a "Grow FAQ" link... just have a FAQ link... and put about ten questions in it like... "How do I add pictures to my posts?" or "How do I delete my post?" or "What is rep and how do I get it?"....
Number one rule in all of this is... I hate to say it... "KISS" Keep it simple stupid.
Hope this is of some use.
nongreenthumb
Well-Known Member
In a word...no
nongreenthumb
Well-Known Member
Don't look until I say, hey i finished moving all the posts, i dont need posts like this. Yes there are posts everywhere, but its only because the categories are in order for the first time that you can see where things are not supposed to be.
All i did the first time was re order the categories, i didnt move any articles, last night i spend 3 hours moving articles in the correct place, as i said its a mess, im on page7 out of 34 for moving articles, there is lots of double articles also.
I say finished then you can look for bad articles.
nongreenthumb
Well-Known Member
I mean your not helping so if you dont mind a bit of quiet for a while and the numbers are staying
nongreenthumb
Well-Known Member
Constructive is the key here. Not counter constructive, I'm still trying to sort out the mess it was left in.
mogie
Well-Known Member
You mean the condition I left it in.
I was asked to put FAQ together from nothing but a few posts about worms. I did the best I could with no help from anybody here. Nobody got together to help suggest catagories. At least you are getting help.
You do need to run spell check. Look at your catagories.
I was asked to put FAQ together from nothing but a few posts about worms. I did the best I could with no help from anybody here. Nobody got together to help suggest catagories. At least you are getting help.
You do need to run spell check. Look at your catagories.
nongreenthumb
Well-Known Member
Look mogie if your just going to bitch because someone had to go and redo what you've done then its falling on deaf ears. I am busy and have work to do, so stop grabbing my attention for meaningless chatter.
nongreenthumb
Well-Known Member
I live in England, you live in America, We both speak "english"
In england certain words are spelt different.
If i have made some spelling mistakes then so what, it will get corrected.
Be useful and go and watch angel or something