technical lighting question for experienced growers

[auto guerilla]

Hi all,

I'm using a 150w mh light for my breeding tank but do all my real growing outdoors. just wondering if you were to use metal halide light from start to finish which color spectrum you would use. i'm currently using 4000k mh bulb. i know what the individual color temps do and how they impact the growth stages but like i said if you were to use one bulb right through which would it be. this is a hard question because all mh bulbs have such a large color spectrum but i would like the one with peaks in the best ranges. i'm thinking the 3000k? help would be much appreciated but no inexperienced knowledge please..thanks

 

[auto guerilla]

lotsa views no replies. cmon someone must have experience with different metal halide bulbs. im after the best spectrum to use right through the grow for autoflowers so want to know which kelvin rating bulb produces the best all round spectrum for this. could be 3000k 4000k or even the blue ones 5-6000k im just not sure. i know they will all see them right through just wondering if one is far better than the others.

 

[RotoRip]

If you wanna run it through the whole cycle the best would be a HPS. But if you wanna stick to the MH you should use one with a low temp colour (yellowish, 3-4k K). If you want to use a MH just for veg I think you should get a higher temp bulb (6k K). Never used MH, though. But in theory white light - veg, yellow light - flower. At least I've done it like that with CFL lights before.

 

[Muddy]

If you want one bulb for the whole grow, you need to be looking at HPS, not MH. MH, no matter what spectrum, isn't going to give you near the yield of an HPS. The newer HPS bulbs have expanded blue spectra to provide better veg growth, still not up to a MH but certainly sufficient for the short veg period that autos have. I'm using a 600 watt Digilux and getting excellent results.

 

[auto guerilla]

is there anyone who has used mh light right through for an autoflower grow? if not then this will be good experiment

 

[auto guerilla]

hey muddy soz i must have written that just as you were replying. yeh i wish i had gotten a hps. i have always grown outdoors and still do. this is just a crack at indoor seed production so i can keep up my grows. what about a 3000k mh bulb, that would have to have a close color spectrum to hps bulbs wouldn't it? do you think this would help? thanks for your reply

 

[mitch_connor]

I remember from awhile ago, SAH posted up a pic of an AF grown all the way through with MH, It looked decent.

Sorry cannot remember the thread it was in or the spectrum of the bulb though

 

[skullznroses]

You want bud, so go with a Budding spectrum! Sacrifice efficiency vegging for a warm red bulb. It will veg fine, and bud perfectly. Sounds like you know what warm spectrum means. I did this exact thing.

 

[skullznroses]

At high enough watts you can do it either way. My friend uses HPS for both (with stringier plants, having big buds), I use grow spectrum T5 tubes for vegging and an LED for flower at the moment, the variety is limitless. There can be an adjustment period between spectrums too. Either HPS or MH is better then fluoro, in general due to higher intensity. The real gurus will tell you intensity is the king property.

Metal Halides are great for vegging,, i.e. heavy dark green growth with short internodes and thicker stems,, can be blue tinted in color, perhaps in the correct range according to common cannabis spectrum charts around 3000k. I recommend buying a switchable ballast if you aren't doing a perpetual harvest. Once again, I have done this myself.

 

[auto guerilla]

hey mitch if you remember that thread let me know thanks

thanks skullznroses i was thinking to put the 3000k mh bulb in to make do the best with what ive got but was just wanting someone to verify this so thanks. can i ask what results you got using mh using what color temp bulb

i know the basic thing to do would be to run a hps bulb but like everyone these days i want to spend as little as possible and have mh light and ballast.

 

[PuReKnOwLeDgE]

HPS conversion bulb, fits in 400MH ballast.

 

[mitch_connor]

Sorry bro, my bad the plants i mentioned from sah were actually done under cfl..

but the pics are still there.. https://www.icmag.com/ic/showthread.php?t=124436

 

[Muddy]

I've no personal experience with those bulbs so can't really comment. Look into the conversion bulbs as pureknowledge suggested.

hey muddy soz i must have written that just as you were replying. yeh i wish i had gotten a hps. i have always grown outdoors and still do. this is just a crack at indoor seed production so i can keep up my grows. what about a 3000k mh bulb, that would have to have a close color spectrum to hps bulbs wouldn't it? do you think this would help? thanks for your reply

 

[vicious bee]

Why not just go with what you have already. If your growing for seed. 5-10% difference will mean nothing to you.

 

[skullznroses]

The MH for budding is worse then HPS for vegging, but not the end of the world, so I still say if you want one bulb choose HPS. Still, I have even read of people who bud with the MH specifically and purposefully. Some special kink in their system where they wanted a certain amount of growth during the flowering period... to fill a space or something perhaps!?!

Otherwise I would say you know too much... gotta test this stuff so you will KNOW too! Trial and error is the only way to wisdom or big buds.