19 plants :) quick question

Discussion in 'First Time Marijuana Growers' started by ap7309, Feb 3, 2012.

  1. hi,
    I have 19 plants under 2 400watt duel spec bulbs will this be enough light? Essentially 9 under each light.

    Cheers
     
  2. Depends more on the space you take up with the plants than anything. A 400w HID light has a footprint of 2x2'. So you want to try and keep your plants in a 4x2x2' area in order to give your canopy the max amount of lumens your light gives off. If you do a sea of green style grow it could work, otherwise it could get crowded.
     
  3. the only way that will happen is if you train them in some way... like a scrog

    I let my plants get big, and 2, 600w lights barely covered 6 of them.
    keep em small, and its possible i suppose
     
  4. If it were my grow I would bump that light up to two 1000W. You will get WAY more bud production with more light.
     
  5. 600 watt lights are actually superior to the 1000 watt lights, at least in terms of efficiency. You can get a 600 watt light with roughly 2/3 the lumen output as a 1000 watt, at a far more reasonable price. I'd say what light(s) he should buy depends on his grow space, at least for the first factor.
     
  6. I agree that there are many ways to grow plants to different sizes, so you need to match up the size of the grow space and amount of light you have. Typical rule of thumb is 1 sq ft per plant and minimum 50w per sq ft of HID (make that 100 actual watts for CFL), and then you can figure out how many plants grown which particular way will meet that.

    Left on their own, 19 plants would take up about 19 sq ft, so you would need at least 1000w of HID. A pair of 600w would be adequate, even better would be three of them, bumping you to nearly 100w per sq ft. If you don't have that much space, then possibly the lights you have are matched to your space and you either should have grown fewer plants or you will need to put them to 12/12 soon so that they stay small per plant but can be packed in to create a full canopy (SOG).
     

  7. I agree the space will be the deciding factor.

    However, the effeciency of 600W HID lighting is highly exaggerated. You can prove this very easily.

    The power company measures Watts so you want to track wattage usage.

    Using Hortilux's ratings from their website for their bulbs we get these values:

    LU600S/HTL/EN\tLumens = 88,000\tHours of life = 16,000

    LU1000B/HTL/EN\tLumens = 145,000 Hours of life = 24,000

    If we do the calculations:

    Lumens per watt (600W bulb) = 88,000/600 = 146.67

    Lumens per watt(1000W bulb) = 145,00/1000 = 145

    I use 1000W for four plants in my Undercurrent setup. Here is my reasoning...

    Why grow 19 plants and use all those nutes if you are not trying to get a large harvest. Why not maximize all environmental factors to get the biggest possible harvest - THERE IS WHERE THE EFFICIENCY IS.
     

  8. Hey there:wave:

    I see you have some great answers already, but would like to chime in as well, but first I need some more info..:confused:

    First are your 19 from seed or clone? Second do you plan to vegg? Third how much room do you have to work with?Do you know strain? And finally can you post a pic of a few of your girls?

    Personal suggestion.. I work with a 600 and vegging plants to a height of 2-2 1/2 feet before flowering.. Using a training technique I can usually fit 4 comfortably and 5 pushing it..

    With 800 I'd suspect probably 6 comfortably with 7 pushing it if working with large girls or 9-12 smaller girls..

    The training will help increase yield, but the strain and amount of light are what will get you there..

    If you want to stick with 19 and not increase your lighting though I'd check out cloning and the 3 ounce grow we have going down..

    See ya around the city.. :wave:

    :smoke:
     

  9. This statement isn't 100% true. 1000w HID can produce more lumens than 2 600s HID's because it isn't like:

    55,000lumens + 55,000lumens = 110,000lumens

    it's

    55,000lumens + 55,000lumens = 55,000lumens.

    So a 1000w has more initial lumen output meaning that the more intense light is still a 1000w HID. 600w's are efficient in the energy saving market but if you are growing 19 plants for profit even, you should upgrade to atleast 2x600w or atleast 1x1000w as you'll produce more tighter buds with better growth overall.
     
  10. Silicity, I'm pretty sure you're kind of on the right track. I think the light intensity formula is a logarithmic one.

    Although, it seems like the application isn't adding up the lumens because they are both pointing at the same spot. It's rather that the 600s are covering two different areas which could equal the same area that the 1000 watter is covering.
     


  11. No. 2 - 600s will produce more light than a single 1000.
     

  12. Well, I think your both sort of right. Lumens are a bit tricky in the real world. As we know, a Lumen is a measurement of the intensity of light; one lumen is equal to the brightness of a candle at 1 foot away.

    Where this get tricky is obviously farther away from the light source the lumens drop. So when we look at the Hortilux bulbs again we see that two 600W HPS bulbs have a total output of 176,000 lumens compared to a single 1000W at 145,000, a total of 31,000 more lumens AND (the important part) spread over a larger area.

    The bottom line is this - 19 plants take up a lot of space. Lower wattage HID lights will have a problem covering this area well.
     
  13. [quote name='"samson32"']

    Hey there:wave:

    I see you have some great answers already, but would like to chime in as well, but first I need some more info..:confused:

    First are your 19 from seed or clone? Second do you plan to vegg? Third how much room do you have to work with?Do you know strain? And finally can you post a pic of a few of your girls?

    Personal suggestion.. I work with a 600 and vegging plants to a height of 2-2 1/2 feet before flowering.. Using a training technique I can usually fit 4 comfortably and 5 pushing it..

    With 800 I'd suspect probably 6 comfortably with 7 pushing it if working with large girls or 9-12 smaller girls..

    The training will help increase yield, but the strain and amount of light are what will get you there..

    If you want to stick with 19 and not increase your lighting though I'd check out cloning and the 3 ounce grow we have going down..

    See ya around the city.. :wave:

    :smoke:[/quote]

    That's for all the replys guys.

    The plants are all greenhouse seeds great White shark and all from seed no clones. The room size is 10feet x 8feet ( 3 meters x 2 meters) and have high roof so no problem with height, the walls are totaly covered in mylar and the room has a fresh air supply. The room temp is 80 degrees. The plants have been on veg 18/6 for about 3 weeks and are about 1.5 foot ish high. There looking really healthy and are growing great so am reluctant to change. I'll post pics after this. What us think I should do ?
     
  14. Well said... this is what the OP needs to consider
     
  15. There 400 watt hps bulbs not hid just 2 make that clear :)
     
  16. [quote name='"ap7309"']There 400 watt hps bulbs not hid just 2 make that clear :)[/quote]

    HID stands for High Intensity Discharge

    HPS are HID lighting just fyi
     
  17. [quote name='"ap7309"']There 400 watt hps bulbs not hid just 2 make that clear :)[/quote]

    HPS/MH = HID....just to make that clear.
     
  18. Anyone have an answer relating to the information I posted that's not about my detrimental knowledge of lighting terms?
     
  19. That 800w will work fine, would be better if you added some supplemental lighting. Maybe some CFL's in there as they're.much cheaper than HID lighting.
     
  20. [quote name='"HipHopFiend"']That 800w will work fine, would be better if you added some supplemental lighting. Maybe some CFL's in there as they're.much cheaper than HID lighting.[/quote]

    Thanks For the help :)
     
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