Who likes numbers?

Discussion in 'Indoor Growing' started by davejohnwright, Jul 6, 2007.

  1. davejohnwright

    davejohnwright Registered+

    Alright I've been researching, brain storming, tokin', and drinkin', trying to figure out how to put my lighting system to it's optimum use. I'm working with a 1,000w HPS system. Thats with a MH conversion bulb, and eye hortilux HPS bulb
    I've figured the numbers with 3 possible garden sizes 4x4, 4x5, 5x5. I'll start with the brightest.

    4'x4' area=16 square feet or 62watts/ square foot
    HPS=9,062 Lumens/ square foot
    MH =6,562 Lumens/ square foot

    4'x5' area=20 square feet or 50watts/ square foot
    HPS=7,250 Lumens/ square foot
    MH =5,250 Lumens/ square foot

    5'x5' area=25 square feet or 40watts/ square foot
    HPS=5,800 Lumens/ square foot
    MH= 4,200 Lumens/ square foot

    With some research I found a thread at marijuana.com that was saying the lumens to keep a plant growing was
    Minimum about2,000 Lumens/ square foot
    Mid-range about 5,000 Lumens/ square foot
    Optimum about 7,000-7,500 Lumens/ square foot or higher
    SOURCE= Lamp Lumen Data - Page 2 - The Garden's Cure

    I know I've seen a thread discussing how much light is too much, but I cant find it, anybnody?
    I'm thinking of going with the 4'x4' area to get the most intensity out of the lighting system but 6,562 Lumens for veg, and 9,062 Lumens for flower seems like I may be pushing too much light. But this may be suitable considering I want some big mother fuckin' (4'-6') plants, of the highest quality possible.

    Also I'm thinking of going with Mandala's Kalichakra, and/or White satin. And I will be using organic soil. Probably a 2-3 month veg to get them nice and big.

    Anyone have any thoughts? Ideas? Suggestions?
    • Like Like x 3
  2. stinkyattic

    stinkyattic CultiModerVatorAtor

    You are a bit more sophisticated than some of us, lol....
    I just go by the 50 watts of HID per square foot, and use the best bulbs I can find to squeeze out a couple more lumens.
    I'm happily running 1400w HPS in a 5x6 space.

    Your issue is going to be DISTRIBUTION, since you want big ass honkin' bitches. If I wanted to grow that style, I would switch to 4 vertical-burning HPS600s in parabolic reflectors. ATM my plants are under a single 1000 and a 400 (when they first enter the flower room), and they have to be bent over short to take advantage of the light. With multiple points of light, you get the luxury of side lighting to your big bushes.
    Just some thoughts. I think BlueBear- who was growing BIG plants- was running parabolics.
    • Like Like x 1
  3. rhizome

    rhizome Registered+

    Well, issues w/ light distribution and airflow...

    If I were running a whole bunch of cuttings, I'd probabley go w/ the 4x4, because I'd know that I had plenty of overhead room for stuff like carbon filters, oscillating fans, etc. I'd be able to cram all that crap up over the reflector and still know that I'd be able to keep the reflector high enough over the plants to keep the distribution pattern sort of even-ish.

    Doing smaller #'s of larger plants- you're gonna get tight on room by the time you hit flower set. Going to the 5x5 does cost you some intensity, but it buys you a whole bunch of room, allowing a certain amount of relected sidelight off the walls.

    Also, you have to balance things on a total room yeild basis.

    Let's say (purely for conjecture) that intensity and yield per square foot are directly ( 1 to 1) correlated. Let's also say, ( and I am making these #s up) that your cultivar of choice will produce 1 oz dry per square foot @ 9,062 Lumens/ square foot. Your 4x4 will produce a lb. ( 16sq'x1oz)

    At 7,250 Lumens/ square foot, ( 80% of above) each square foot will produce .8 oz, assuming a 1 to 1 relationship. Your 4x5 will produce a pound (20 sq'x.8oz)

    In the 5x5, the plants are receiving 65% the intensity of the 4x4. If we follow our admittedly-all-made-up formula, each sq' will produce .64 oz. Your 5x5 will produce , oddly enough, a pound. ( 25sq' x.64oz).

    I love linear relationships. They're so...symmetrical...

    So a lot of it comes down to personal management issues, grow style, cultivar chosen, etc. It's a lot easier to manage environmentals in 200 cubic foot room (5x5x8) than it is in a 128 cf room(4x4x8). Larger spaces are more tolerant of mistakes, easier to work in, etc.

    It sounds like you're not that familiar w/ the genetics that you'll be running. I'd definately go for the larger space- It really bites to realize that you timed things just right to peg the room at 70% stretch, but the plants are gonna do 140%.

    I like a k per 4x4 if you're running say, 4 of them in an 8x8 room, but cramming one into a 4x4 presents management issues. Make it easy on yourself- go a little big.
    • Like Like x 2
  4. khronik

    khronik Registered+

    Well, Mandala's catalog recommends 400 watts per square meter for Kalichakra. That works out to about 37 watts per square foot, which is pretty close to what 5' x 5' would give you. If you want really huge plants, the limiting factor often seems to be soil quantity rather than light. Do you have any 10-gallon planters? Trash cans maybe?
  5. PharmaCan

    PharmaCan Registered+

    DJW - Check out this thread - Sealed Room 3lbs/light. He's got the same light concentration as you are contemplating - except he's doing an 8'x8' area. This isn't exactly the same kind of grow you are talking about, but Tranoble seems to have his shit dialed in pretty tight and you might get some good ideas from the thread.

    PC :thumbsup:
  6. davejohnwright

    davejohnwright Registered+

    Alright I slept on it, and I'm thinking I should start the veg cycle in the 4x5, or 5x5 since there will be more plants before I weed out the males, and they may not like the intensity so much at that age.

    For the flower cycle I'm thinking I should keep 4 plants in a 4x4 area, or a 4x5
    depending on if space becomes an issue, and if needed I can LST/ supercrop to use all available space/ keep them from overgrowing the garden. Vertical space is no issue since I have 12' of head room in the spot I have picked out.

    Your right Rhizome I am unfamiliar with Mandalas genetics. I have read wonderful things about them though, and they are the cheapest seeds I've seen anywhere on the net, so I think they deserve the opportunity to prove themselves in my garden. I may have jumped the gun when I stated a 2-3 month veg cycle, if Mandalas seeds are anywhere near as good as I've heard it wont take that long at all.

    I've still got plenty of time to figure out what I'm gonna do. I'm patiently waiting for the summer heat to die down before setting my garden back up. Plus my lady has been on my ass to grow her some mushrooms, so I'll start/ finish that project first, even though i myself am immune to psilocybin.
  7. rhizome

    rhizome Registered+


    W/ that kinda headroom, have you thought about going to a parabolic? Go 6x6 no prob, give ya 3x3 per tree.
  8. PharmaCan

    PharmaCan Registered+

    Can you explain why you said this. (Real question, not argument - it's sometimes hard to tell these days. :D)

  9. davejohnwright

    davejohnwright Registered+

    I dont understand either. I figure my rectangular air cooled hood would work nice to give me a square garden. Parabolic would give me a round garden, if I'm not mistaken. And my geometry is too rusty to figure those numbers. lol
  10. davejohnwright

    davejohnwright Registered+

    Hey pharmacan the link you gave isnt working. I seem to remember seeing that thread before, but am having trouble locating it.
  11. PharmaCan

    PharmaCan Registered+

    Last edited: Jul 6, 2007
  12. khronik

    khronik Registered+

    I wonder why this is sticky? A moderator mistake maybe?
  13. rhizome

    rhizome Registered+

    The parabolics give a very even distribution of light over a larger area. I've found that they give a better pattern over large plants, as the light is reflected downward at a greater distance from the bulb. Works nicely over large plants, as long as you can keep the reflector a couple of feet over the crop.

    Feel like I should do some cool diagram in Paint, but I don't have the chops.

    I didn't notice that your hood was cooled- so you like to fly it in pretty close? Doing large plants, I've always found that things worked best if I flew the reflector a little high, to keep the plants from shading each other- but you need headroom.

    I have no idea why this is sticky.
  14. oldsanclem

    oldsanclem Registered+

    Rhiz is right on the even light of a parbolic works like a charm.
    Take any photogram and darken a print and you will see the flat spots and hot spots of box parking light devices. :(
    I always love things how they work and bla blabs (that just talking and no data to back it up] :(
    I have used parabolics for a few decades and average 0.468 grams per watt day in year out. In a plant them in buckets chop to fit, bloom to harvest. :D
    scrog is to much work and I grow with a computer and lazy.
    grams / watts/months
    if you have 1000 grams finished using 1000 watts / harvest every 2 months its 0.5 g/w/m:thumbsup:
    You must add months as you could grow a plant for 2 years and bloom for 4 weeks and get one hell of a number. :wtf:
    "grow for effecency , the fun comes at harvest" SanClem:Tomcat:
  15. davejohnwright

    davejohnwright Registered+

    I keep the light a good couple feet from the top of the canopy, I've experienced a problem on my first grow with the colas bleaching out on me, sucks when you lose the best part of the plant. Plus yeah I dont want them shading each other out.

    And as for it being sticky, I have no idea, but it sure has been an interesting thread so far, I'm sure many people can learn a thing or two from it.
  16. Weedhound

    Weedhound Registered+

    Go with a cool tube if you want to eliminate shady spots for growing. IF you have a way to deal with the heat and cooling.
  17. ...gas...

    ...gas... Registered+

    very interseting , i am running 2 x 400 watt over 2 plant s in a space 1.8m length by 1m wide by 2.2 m height , temp s a perfect , ventalation is good , yeild is very good , in hydro , is that 2 much or 1 600 would do ? thanx 4 any help :thumbsup:
  18. extinctx11

    extinctx11 Registered

    Just to throw this out there, I've read that lumen output also has to do with distance, so if you are assuming a certain number of watts or lumens per foot, you also need to take into account the distance of the lights at the time... a 250w light might only be 100w by the time its light gets to the plants if its too far... and visca versa.

    There is also a coorolation with wattages, I noted my 250W actually pulls about 450Watts and my 400W HPS pulls about 700 Actual watts, so keep this in mind when planning breakers and fuses etc...
  19. davejohnwright

    davejohnwright Registered+

    The worry of shading is that I want my plants big, and I want to minimize the lack of light on the lower branches, not too big of a worry since big plants equal big colas, and as we all know they are the best part. But I dont mind smoking lower buds, so I want some of them too. I'm mostly just trying to figure out the most efficient way to work with my light mathematically, it's not working too well though. I should get a light meter, but I'm poor, so I'll probably end up doing like I always do and follow my intuition.
  20. davejohnwright

    davejohnwright Registered+

    I started this thread thinking about the lumen decrease due to distance http://boards.cannabis.com/advanced-techniques/123243-anyone-have-formula.html . But the only way to figure out how many lumens are where is with a light meter it seems.
    And I know about how decieving the wattage of light you use is compared to the power it uses, but thanks anyways.

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