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Thread: Lighting the Way for CP's

  1. #1
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    Lighting the Way for CP's

    Lighting the Way for CP's

    There is a lot of indesicion over what lighting to use for CP's, and why. Should you use good old fashioned sunlight? Or do you need to supplement with lighting? What lighting should you be giving your CP's?

    Read on and find out!


    Natural Light
    Incandescent Light
    Fluorescent Light
    Recommended Light

    Natural Light

    Sunlight is what CP's, and every other plant, get in their wild, native habitats. Some plants get lots of light, some plants get it in moderation, others get very little, but all plants get some sunlight, and nearly all cp's get quite a lot.

    Natural light is 'white light' or light that is made up of all the different light spectrum colours. All light is split up into different colours; red, orange, yellow, blue, green, indigo, and violet, and 'white light' is all of these colours combined. Plants need light from the red and blue range the most, with the red range used only a little bit more than the blue range, and they use very little yellow or green light.

    *On an average sunset or sunrise there will be about 400 lux
    *The minimum amount of lumens per average day is 30000 lumens per square metre.
    *The maximum amount of lumens per average day is 100000 lumens per square metre.
    *Direct sunlight is equivalent to 100000 lux, or 100000 lumens per square metre.
    *Cloudy sunlight is equivalent to 30000-70000 lux, or lumens per suqre metre.
    *Very cloudy sunlight is equivalent to 10000-30000 lux, or lumens per square metre.
    *Rainy day sunlight is equivalent to 7000-10000 lux, or lumens per square metre.

    In the wild, most cp's have a growing season where they will have cloudy to direct sunlight nearly every day. This 'growing season' can extend for as little as 3 months, up to the whole year. The closer a plant's natural habitat is to the equator line, the more likely it is that the plant will need to have consistent cloudy-direct light all year round. Also, plants on high altitude, exposed mountain tops will be more likely to have 'growing seasons' with high light.
    Plants which have habitats further away from the equator, will probably have a period, of equal, lesser, or greater length, where they have dramactically or noticeably less light compared to their growing season. During this time, the light levels will more likely be from rainy day sunlight to cloudy sunlight, with occasional direct light.

    As a general guideline:

    * 'Tropical' and 'subtropical' plants will have 'growing seasons' and 'non-growing seasons' with similar light levels, and usually these plants will have light levels from cloudy-direct light.

    *'Temperate' plants will get cloudy-direct light in their 'growing season' and rainy day-cloudy light in their 'non-growing season'.

    *Alpine plants will get direct light in their 'growing season' and no light-very cloudy light in their 'non-growing season' because they get buried under snow.
    Forest plants will get cloudy-direct light, but this light will have been flitered by the tree branches before it reaches them.

    *Mountain-top plants near the equator will get direct light all year round, and may not have a 'non-growing season'. The only seasonal fluctuations may be in the time length, which may be an hour or two less, for half the year. Occasionally these plants will get very-cloudy or rainy days.

    Conclusion:This means that no matter what CP you grow, for it's growing season, however long that may be, you need to give it at least 30000 lux for it to preform characteristicly of its species.
    Plants may be able to survive on 10000 lux at a an absolute minimum, but they will be sickly, unhappy, and will not preform to their best. They may even die.


    Incandescent Light

    Incandescent bulb's are the lighting used in most household fixtures. These light's are characterised by an orange sort of glow or light. They can also be coloured, but most used in household fixtures are just standard, incandescent bulb's. They come in various wattages, which are a measurement of the power output of the bulb. The abbreviation for this sign is W. Common W are: 40W, 60W, 100W, and less commonly 150W.

    Incandescent bulbs work by having a enclosed space filled with an inert gas. They have a very thin wire inside this enclosed space, which a circuit of electricity runs through, an heats up the thin wire. When the thin wire is heated, it glows, thus the light that the light bulb gives.

    These types of light are weak compared to sunlight and fluorescent light, and for this reason they are unsuitable for cp use.

    Also, incandescent bulbs produce light mainly in the red range of light, with very little in the blue, so they are unbalanced for plant growth, and unsuitable on their own.

    Another factor is that compared to natural sunlight and flourescent lights, incandescent do not last very long, and use more electricity, and therefore more time/ effort/ money to run.

    Combine this with the fact that the light given off by these lights is practically useless to plants, and it means these bulbs will not sustain plant life.

    Flourescent Light:

    Fluorescent lights produce a different sort of light, and are not as commonly found in houses as incandescents, although they are just as common, or nearly as common as incandescents i shops. They come in a variety of fittings, many of which will easily fit in a household, incandescent fixture without problems. These include: screw in, bayonet,

    Fluorescent lights work on an entirely different principle to incandescent ones. Instead of eletricity heating a wire, the electricity excites the gas in the fluorescent light, which is mercury vapor, and mixes it with another gas in the bulb, neon or argon gas, to produce a change which results in ultraviolet light being produced. This then causes another material in the tube, a phosphor, which is a material that glows for a while after the above process, to glow. These types of light need a 'ballast' which regulates the amount of electricity flowing through to excite the gas, however many light bulbs come with these already built in.

    Fluorescent lights produce a small amount of red light, as well as orange, yellow, green and blue rays. They are a good source for artifical plant lighting, however they do not produce enough red light for plants to thrive on their own, and are best supplemented with either some natural light, or incandescent light to provide the essentially needed red light.

    Fluorescent lights last for quite a long time, up to 10 times as long as the standard incandescent bulb, and do not use nearly as much electricity and incandescent bulbs do.

    Recommended Light:

    Low Light Plants: CP's generally do not fall under this category, unless they are dormant.
    Medium Light Plants: 45 or more Watts per square metre or 25000-75000 lumens
    High Light Plants: 60 or more W per square metre or 75000-100000 lumens

    Hope this helps!
    Drosera Arcturi-The Alpine Sundew...

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  2. #2
    Tropical Fish Enthusiast jimscott's Avatar
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    Thanks for providing this information. How uch lighting and what kind is required for germinating sundews?

  3. #3
    Av8tor1's Avatar
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    Nicely written post, however... please forgive me but the data is somewhat obsolete. Lumens are not really a good metric to use when comparing light sources for plant growth. Understandably, this has been some really hard "tribal knowledge" for us to get past.

    A lot of the problems originated from the statement "there is no diff between gro bulbs and daylight bulbs"

    Well that is true... If you are talking about the so called "broad spectrum" halophosphor grow bulbs (which are nothing more then repackaged, repriced, high CRI daylight bulbs), but totally false if you are talking tri-phosphor gro bulbs ( the real gro bulbs that appear purple-ish)

    What happened is you had someone who did not understand the physics of light and the diffs between bulbs make a statement and wham.... everyone accepted it and it became part of our culture. While most fluorescent bulbs will grow plants, there can be a great performance (as much as 20% or more) difference between bulbs...

    PAR and PUR are a much better metric to go by, lumens can actually be used as a measurement of the light a plant cannot use efficiently (heavily biased toward the green/yellow wavelengths)

    A high lumen/watt light is a big shotgun, a low lumen/watt light but one that has the right PAR/PUR is a sniper rifle,

    Yes, either will do the job... yet one has very low lumens, appears dimmer and uses much less energy... it has to do with efficiency measured in PAR/Watt and PUR/Watt

    Interestingly, all things being equal then probably the greatest variables are reflector design and bulb diameter, this alone can affect the amount of light the plants get by as much as 300% These gains in efficiency are free once the initial investment has been made.

    Of course for maximum energy transfer, keep your bulbs as close to the plant as possible

    There is also a point of diminishing return, if you increase light then you need an increase in nutrient and CO2 intake. Even then at some point photo-inhibition will still become an issue

    Have a look at this article written by a true guru of plant lighting, Ivo Busko
    (Ivo Busko works at the Space Telescope Science Institiute and created Specview, a tool for 1-D spectral visualization and analysis of astronomical spectrograms)


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