1. Grasscity.com August contest: Subscribe to our channel on YouTube to be entered to win a PAX 2 Vaporizer! Winner will be announced Sept 1st
    Dismiss Notice

Will addding bulbs add more Watts and Lumens?

Discussion in 'Lighting' started by ThaiTaniumKush, Jul 23, 2011.

  1. So. If you have a 36w 2,690 Lumen Fluorescent T8 tube. Will adding..4 bulbs to your grow room add up to 144watts and 10,760 lumens to your room. Or is that just a myth? I know stupid questions. Just want to make sure.
  2. Yes, both wattage and lumens are additive.
  3. Sweeeeet! ok thank you so much ^^
  4. Check out the 'Is more light better?' thread.
  5. So it Lumens more important then Watts?
  6. Yes. Between lumens and wattage, lumens definitely is closer to measuring what we want to measure. Actually neither is measuring what you really want to measure, but what you want to measure is very difficult to do so. Wattage and lumens are used to stand in its place.

    All you really are concerned about is the amount of light the plant is receiving, and in particular the amount of light in certain important color spectra. It would take a very fancy and expensive light meter to measure that.

    Lumens is a measure of the light output of a bulb, but it is a measurement at a fixed distance from the bulb (whereas in your grow space the bulb might actually be closer or farther away) and also it is adjusted for measuring the light visible by humans, not all light output. But, we still use "lumens" as a proxy for actual light output -- more lumens is presumed to mean more light in the plant's key spectra.

    Wattage is simply a measure of electrical consumption. Your refrigerator consumes watts, as does your microwave oven, your hair dryer, your computer, etc. But we use watts to stand in for actual light measurement because with certain types of bulbs we know what their lumen output is and we know from the collective experience how many watts of a given type of bulb will work well, will work barely, and will not work for growing MJ.
  7. It doesn't seem that more bulbs would add brightness beyond the maximum brightness of the present bulbs. So that if you started with a 100 watt bulb and it's 100watt brightness... adding more 100 watt bulbs wouldn't make the space be brighter than a 100 watt bulb. But adding bulbs would increase the brightness of the areas where the light had faded lower than the 100 watt brightness.

    A room full of 1,000 5 lumen light-lights doesn't seem like it would be as bright as a 5,000 lumen bulb. It would just provide fuller coverage of 5 lumen light.

    It seems that way at least.

    But the real Q is... are lumens cumulative for the plant's sake?
  8. Why not?

    Enter a dark room and turn on a lamp. The room is now receiving that one lamp's worth of "brightness." Now turn on more lamps, doesn't the room get brighter? Why would light reach some maximum limit from a lightbulb?
  9. #9 Swami, Sep 25, 2011
    Last edited by a moderator: Sep 25, 2011

    Lumens are definitely cumulative. This is how solar collecting mirror arrays work.

    However, this does not answer your question as to plant growth response - and it is one that should be answered by our community.

    Here is my proposal for a controlled experiment:


    1. Two nearly identical grow rooms/spaces that are light segregated.
    2. A minimum of eight identical clones.
    3. Three light sources: two identical 1x lumen lamp and one 2X lumen lamp.

    Use the 2X lamp directly overhead of four of the clones.

    Use the two 1X lumen devices in any configuration except for a double overhead. Perhaps offset and angled, one on each side or one overhead and one side. Place this over the remaining four clones.

    Grow as normal and weigh the yield.

    For this test, I think the optimal light choice because of consistency would an 8 bulb T8 vs. two 4 bulb T8s.

    Any volunteers? I would but not have the space.
  10. #10 transverse, Sep 25, 2011
    Last edited by a moderator: Sep 25, 2011
    The entire room area does get brighter, but that is not the question exactly.
    With 1 bulb lit, there is a brightness level in the area directly next to the bulb, that's the maximum brightness from that bulb; call it X brightness. Now.. add a second identical bulb next to it. The area of X brightness will be larger, but will any area be brighter than X?

    For 2 bulbs next to each other, which one of these would happen?

    The first scenario shows increased coverage of brightness, but not increased brightness.
    To me it looks like the second scenario, with a brighter area in the center would require a 3rd bulb that has a brightness greater than each of the bulbs already there.
    (But really what's important is the effects on a plant, which might be different than what's visible as brightness to the human eye. i dont know)
  11. Dude, already answered. Brightness IS cumulative as exemplified by solar collector arrays. Don't believe it? Get a parabolic mirror or a magnifying glass and go outdside and fry something.
  12. #12 transverse, Sep 25, 2011
    Last edited by a moderator: Sep 25, 2011
    With solar mirror arrays, magnifying glasses and such, they work by concentrating the light or heat, from a set area into a smaller area... giving it more density intensity and heat. Combining multiple bulbs won't concentrate the light I don't think.

    Yes, an actual experiment/experience would be the best plan. Even with the image in the post above, it may not be brighter, but the bottom line is the effects on the plant.
    Actually, I'm sure some posters have already done experiments, even if just incidentally as they changed their bulb set-up with successive grows. (or if there are grow journals that used all very low-watt bulbs, that would show what multiple low-wattages can do plant-wise. If a plant grown with only 800 lumen bulbs can near-match a grow using only 2000 lumen bulbs, (all other variable being near equal), that'd show that it's the case.

    -- If anyone knows of any, either comparative side-by-side or subsequent grows, or grows using only 15w bulbs or less, please post links. --
  13. Infrared radiation (heat) acts the exact same as visible light radiation as they are the same thing albeit at different frequencies. This is all basic physics and is not really up for debate nor does this aspect require testing.

    Incidental testing is not the same as purposely testing. Of course there is a huge variable that comes into play. There is a light/response (non-linear) curve and it depends where you are on the curve when starting so doubling the light does not double the plant growth response.
  14. i always saw along the lines of transverse, but It seems i was seriously misinformed quite a few times, it was always being explained to me that lumens cannot add ie, 800lm+800lm is not 1600lm but yet a more intense space of 800lm, i understand where you and toasty are coming from swami but maybe the solar array and magnifying glass talk lost me, but i still cant see adding a few 26w cfl (800lm) to a 150hps(16000) aactually increasing the lumens withing the given space, my brain just is blocking out 17600, anyway to make this easier to understand why?
  15. Huh? Lumens is a measure of intensity. There are no degrees of 800LM.

    Read a book on physics.

    One apple + one apple = 2 apples. 1 lumen + 1 lumen = 2 lumens.
  16. #16 Chrismittty, Sep 26, 2011
    Last edited by a moderator: Sep 26, 2011
    wow thanks for the one apple+ one apple= 2 apples, that completely explains lumens for me. why share info to begin with if explanation of your ideas isnt what your trying to do? Im not trying to be rude but that simplicity seemed almost insulting
  17. I keep tossing this around also, it's intriguing because it's ambiguous.
    But I don't have an array of bulbs, and devices to accurately measure the lumen, or the ability to do side-by-side grows to actually determine the effect on plants.

    This is one point that I have to accept, even though it makes me rethink the beliefs about lumens and light..

    We are all familiar with mini christmas lights

    Given the same sime room, Can any of us imagine putting enough of these lights together to be able to match the brightness of a 1000 watt HPS? If the lumens add together they theoretically they should be able to add up to match a 1kw HPS.

    I guess a question is if, at the very point of light-creation:
    -all bulbs emit the same brightness of light particles(packets), just some bulbs emit more of them
    -some bulbs emit brighter particles than others

    Is the fillament of a mini xmas bulb as bright as the sun's surface.
    If not, then it means that light packets/particles themselves can vary in brightness.

  18. Could also just plug in one light at a time while setting up the grow room. It does in fact get noticeably brighter with each additional light that gets turned on.
  19. An einstein is a unit used in irradiance and in photochemistry. One einstein is defined as one mole of photons, regardless of their frequency. Therefore, the number of photons in an einstein is Avogadro's number, 6.022x1023. Irradiance might be measured in einsteins per square metre per second, if the frequency is well defined, as for a monochromatic source. If the optical frequency is not well defined this is a sloppy misuse of the term irradiance, which is defined in terms of power per unit area.

    The einstein is used in studies of photosynthesis since the light requirement for the production of a given quantity of oxygen is a fixed number of photosynthetically active photons (about nine photosynthetically active einsteins per mole of oxygen formed).

    It is named in honor of Albert Einstein, who in a 1905 paper explained the photoelectric effect in terms of light quanta, now called photons, an idea introduced by Max Planck.

    Photosynthetically active radiation (PAR) is usually reported in microeinsteins per second per square meter (μE/m2/sec), one microeinstein being one-millionth of an Einstein.

    It is also called the energy possessed by one mole or Avogadro number of photons.

    The lumen (symbol: lm) is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. Luminous flux differs from power (radiant flux) in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux measurements indicate the total power of all light emitted, independent of the eye's ability to perceive it.

    The lumen is defined in relation to the candela as
    1 lm = 1 cd·sr
    A full sphere has a solid angle of 4·π steradians,[1] so a light source that uniformly radiates one candela in all directions has a total luminous flux of 1 cd·4π sr = 4π ≈ 12.57 lumens.[2]

    If a light source emits one candela of luminous intensity uniformly across a solid angle of one steradian, the total luminous flux emitted into that angle is one lumen ( 1 cd·1 sr=1 lm ). Alternatively, an isotropic one-candela light-source emits a total luminous flux of exactly 4π lumens. If the source were partially covered by an ideal absorbing hemisphere, that system would radiate half as much luminous flux—only 2π lumens. The luminous intensity would still be one candela in those directions that are not obscured.

    The lumen can be thought of casually as a measure of the total "amount" of visible light in some defined beam or angle, or emitted from some source. The number of candelas or lumens from a source also depends on its spectrum, via the nominal response of the human eye as represented in the luminosity function.

    The difference between the units lumen and lux is that the lux takes into account the area over which the luminous flux is spread. A flux of 1000 lumens, concentrated into an area of one square metre, lights up that square metre with an illuminance of 1000 lux. The same 1000 lumens, spread out over ten square metres, produces a dimmer illuminance of only 100 lux. Mathematically, 1 lx = 1 lm/m2.

    A source radiating a power of one watt of light in the color for which the eye is most efficient (a wavelength of 555 nm, in the green region of the optical spectrum) has luminous flux of 683 lumens. So a lumen represents at least 1/683 watts of visible light power, depending on the spectral distribution.

    Look people, let's make this simple: brighter lights emit MORE photons. ALL PHOTONS of the same frequency contain the same amount of energy no matter the source. The only difference is the number of photons hitting a predetermined surface area. Photons do not interfere with, collide with, amplify or cancel out other photons.

    One candle = 1 candlepower
    One candle + one candle = 2 candlepower

    300 lumens + 300 lumens = 600 lumens.

    Photons that carry the most enery have a lower wavelength; i.e. blue has more energy than red.
  20. #20 transverse, Sep 26, 2011
    Last edited by a moderator: Sep 26, 2011
    I've search for every thread titled with under 100 watts as a grow.

    1x 4200Lumen (68w) bulb - total 4200 lumens
    4x 1600Lumen (23w) - total 6400 lumens (guessing they are 23w since the 92 watts comes from 4 bulbs)
    4x 1600Lumen (23w) - total 6400 lumens
    4x 1600Lumen (23w) - total 6400 lumens
    3x 1600Lumen (24w) & 1x 900Lumen (14w) (86 watts) - total 5700 lumens

    The first thread shows plants that had been vegged for 3-4 weeks under a single 68watt cfl (4200 lumen) cfl.

    Among the threads, there are differences between the grows.. different light distances, soil type, pot sizes,
    room size and reflectivity, and there could be differences in nutes

    .. but even understanding that, the 4200 total lumen grow from the 4200 lumen bulb, looks significantly larger, denser, fuller, healthier than the other grows which had 1.5 times more total lumens.

Share This Page