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Philips 3k Vs Philips 4k Cmh In Flower

Discussion in 'Grow Diaries' started by DemonTrich, Nov 14, 2017.

  1. This is a test of the Philips 3k and 4k cmh bulbs in flower. I'll need your input as well comparing pics. I should be able to match week for week. All done with same strains, same room placement, same temps/rh. I will need to lower co2 from 1200 back to 1000. Lessen the variables.

    Bulbs being tested

    Philips master Greenpower elite agro t12 930 (3k)
    Philips master color cdm elite t9
    940 (4k)

    1 brand new bulb far left (#1) hood. All other bulbs have maybe 1200hrs tops. Fixed hoods, I use cinder blocks, milk crates, or tubs to raise plants between 36-48" tops.

    1 thing I did notice, (may be due to the winter weather, cold basement) my a.c. doesn't need to run as often as my co2 is lasting much longer. I'm betting the 4k isn't as hot as the 3k bulb.

    Here's a link to a past cmh grow.but with the 930 (3k) flower bulb.
    I'l try and get some pics later.

    Flipped 11/2 to 12/12
    I'l take these to 64+ days. I tossed in a cannatonic4 cbd last night. My patients will be needing her soon.
    Last edited: Nov 15, 2017
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  2. gwheels


    I am dying to know if the 3100 is better or the 4000. :)
    DemonTrich likes this.
  3. I'll watch,Im using 3100 in veg.
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  4. GrowGod

    GrowGod BANNED! Supporter

    Can we get mixed spectrum results as well! I jot a 3100 and a 4200 per hood.
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  5. Maybe next run I'll do a 3k/4k/3k/4k.
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  6. So from my understanding you can use both 3k and 4K for flower or veg?is it jus the light cycle that determines flowering?
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  7. GrowGod

    GrowGod BANNED! Supporter

    Yes. Put the lights 12 hours on 12 hours off and your good to go
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  8. You can run any kelvin/spectrum.bulb you like at any time from.seed to chop. Choosing the proper spectrum for said plant type is key.

    Today is 12 days from flip. I hope it' not the "placebo effect" (could very, but I'm noticing a difference already.
    1 less stretch with 4k
    2 tighter nodes with 4k
    3 quicker developed bud sites. I don't remember them.being this nice this early.

    Tomorrow the last of the tubs get removed, and either 1 or 2 nets are going up and weaving the taller tops to match the little shorter ones.
  9. 15 days from flip

    Few pics from tonight
    Controller set to 84*, 1000ppm co2
    Rh avg 65-70% lights out, 65% lights on.
    Need to set up my deheuy in 3 weeks. I don' really worry about rh or lowering temps until the buds start to fill out (week 5ish). Net went up tonight. I'l
    Tuck a few tall ones and hope to even it out a bit more.

    I still believe the 4k lights run cooler (less a.c. usage), less stretch, and closer nodes than the 3k. As far as yields, still 8 weeks away, then cure, so about 11 weeks.

    20171117_203420.jpg 20171117_203414.jpg 20171117_203424.jpg
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  10. I'l post up pics and a report tonight. I ordered 3 new 940 t9 veg bulbs yesterday to replace in my veg room.
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  11. Been swamped lately. Pics are 2 days ago. 20 days from flip. I need to tuck some of the super tall ones a bit down to try and even out the canopy. It' still better and easier than stakes. Every 4th day it's the usual feed or water/silica time. Same as always with the 930 bulb.

    20171124_201034.jpg 20171124_201003.jpg 20171124_201015.jpg
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  12. brazel


    Bro I'm stoked for this grow test!
    In my findings i got better results with 4000k vs 3000k in COB
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  13. brazel


    After i went scrog i stayed there! I love it
  14. Nice comparison,can you tell me what lights are where in the pics?
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  15. All the lights in the pics are the 942 philips veg bulbs. The links have my prior grows with the 930 philips flower bulbs
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  16. Im confused,is 942 and 930 a part number or wattage?
    I thought you were running a side by side here with 3100k vs 4000k lamps or no?
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  17. 942 is their 4k bulb
    930 is their 3k bulb

    This is to test this 4x942 bulb run vs prior 4x930 runs.
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  18. How’s it coming along?
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  19. Excellent!

    I'l post up later tonight with pics. Iirc, today I'll be at 31 days from flip. If it continues on this track, it' gonna be a win win for sure.
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  20. I'l snap a pic of what happens 1 week before you flip when you top. Makes that particular top bud/grow funny. Looks liken it was grown near Chernobyl .
    Brownboi419 likes this.