Flowering with MH

Discussion in 'Advanced Growing Techniques' started by Murdoch, Apr 29, 2013.

  1. I've heard flowering with MH prevents the plants from stretching as much as with HPS but the buds not getting as compact.

    I've also heard that when flowering with MH the buds get stickier. Is that true?

    I'm thinking to use MH next time for flowering but to switch to HPS the last 2-3 to try do get the buds to dense up at the end. Big super sticky buds sounds good to me.

    Has anyone here tried this?
  2. I don't think it's the kelvin that makes the bud, more like that amount of lumens you got on the bud thats important for bud quality and or quanity
  3. Never used it for flower, but hps are putting out more lumens so I cant imagine the MH would be a bigger yield or higher quality.
  4. Well it's not just about the lumens. Plants grow differently with different light spectrum. That's a known fact.
  5. True but the hps i supposed to mimic the summer stage or flowering stage with max lumens, someone more knowledgeable on this subject will have to comment to.
  6. #6 Navarone, May 1, 2013
    Last edited: May 1, 2013
    MH more blue like summer for veg more blue less stretch.
    HPS more red like fall for flower more red more stretch.
    A mix of both during flower is good, ie enhanced spectrum bulbs, can also veg because more blue.
    MH puts out more UV stresses plant makes more trichomes.
    People use uv 10.0 reptile bulbs to add more uv and trichomes. Too much uv burns badly though.
    Not all lumens are equal, it's about PAR light. Google it.
    Speaking in kelvin, hps vs mh, lumen etc get us about 90% there so most don't bother learning about the PAR, but LED growers are targeting only the best wavelengths, so lower lumens but still high PAR.
  7. The difference is in the wavelength of light. HPS puts out a strong discharge in the orange region. Metal Halide emits strongly in the blue region. Flowering plants need light in the orange region. 500W HPS emits more light in the orange region than a 500W MH. (MH puts out more light in the blue region.) So you would need a much high watt HM light to get the same result as a MH.
    Having said that, adding some uv light from a MH or some blue compact florescents will stimulate trich production. Add a few if you can.

  8. This is what I'm mostly thinking about. I know all about the spectrum of the light and that stuff.
    I'm just thinking if anyone has tried this.
  9. #9 DopestDope13, May 3, 2013
    Last edited by a moderator: May 3, 2013
    From experience ive found that flowering with a mh bulb makes them kinda airy, and fluffy so to speak, and not as dense as a plant flowered under hps:). Still good quality, but if I had to pick a bulb to go from start to finish hps all the way. You can get all scientific or just try it and see what happens:)
  10. I've used HPS the entire time (for veg and flower) and it works fine for me. the plant are usually squatty, like I like them.
  11. I am currently flowering using a 1000w MH. I don't have the funds to purchase a HPS and this was loaned to me. They have been under 12/12 for the last 2 weeks, flowers and hairs just starting to grow good. This is my first grow, so I don't have any personal done any other way to compare to, but I do know most the stuff I get that's done indoors is done under HPS, so i'll have that to compare to. I'll keep you updated!
  12. #12 joe 60, May 19, 2013
    Last edited by a moderator: May 19, 2013
    I have tried it and you are right
    MH  less dank but more sticky and has more crystals, plant stay more short and bushy
    HPS more dank and strech plant with a little more yeild (but only if the plants are trainned well or a sog grow)

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