Dual Spectrum Lighting?.

Hi all,

I have always approached this topic traditionally, meaning I lean towards blue and white MH bulbs for veg and of course yellow/red HPS to finish. However, I have been re-thinking this method due to my results under natural sunlight last year. For one, my indica dom began flowering when daylight dropped below 14 hours. This was in late July when natural sunlight still emits quite a bit of blue/white spectrum. Plants finished soon after the Fall solstice, when natural sunlight peaks at red /yellow spectrum. So in effect, outdoor plants are already receiving dual spectrum lighting throughout their flowering periods.

With this in mind, for starters I changed my approach to light cycles during flowering...opting for a gradual reduction as opposed to simply flipping switch from 18 to 12 hours. But I also am thinking perhaps I should add some daylight spectrum to the straight HPS I am using for flowering.

I am fortunate enough to have a TON of bulbs and fixtures, and I could easily add another 600 actual 6500K CFL watts to the existing 600 HPS. Or, I could run both a MH and HPS using 2 ballasts etc.

If anyone experienced in this would be so kind, I'd love to hear what you all have tried or currently using.

TY in advance!

The largest bud nubs I've ever encountered were growing under two 1kw mercury vapour MH HID's subsidized by two 500w hologen's. The smallest nub weighed in at ten grams and the largest nub came in at 33 grams. This was done with a pre-vegged, cloned plant in an eight week flower period, F&D.

bird mcbride said:

The largest bud nubs I've ever encountered were growing under two 1kw mercury vapour MH HID's subsidized by two 500w hologen's. The smallest nub weighed in at ten grams and the largest nub came in at 33 grams. This was done with a pre-vegged plant in an eight week flower period, F&D.

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Interesting, I happen to be 4 days into a gradual flowering and still am running my 600 MH.

Halogens?, is that not a pure blue/white spectrum as well?.

Sunbiz1 said:

Interesting, I happen to be 4 days into a gradual flowering and still am running my 600 MH.

Halogens?, is that not a pure blue/white spectrum as well?.

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They were the kind that went/go into construction lamps, two 500's for $5Can. Very white/high spectrum blue. They throw off a truckload of heat.

bird mcbride said:

They were the kind that went/go into construction lamps, two 500's for $5Can. Very white/high spectrum blue. They throw off a truckload of heat.

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And this grower used only white and blue spectrum throughout entire flowering period?.

The metal halides were frosted and if I remember correctly they were/are considered daylight.

Sunbiz1 said:

And this grower used only white and blue spectrum throughout entire flowering period?.

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The plant went from daylight tube to those lights. The plant had been fim'nd several times and stood about 18"-20" tall when it left the mother room. When started the plant occupied a space about 2' by 2' and very bushy. Yes, you don't need hps to do a grow. but I wouldn't go with the ordinary MH.

I've never seen the results but I have heard of people using hologen car headlights when they first came out.

bird mcbride said:

I've never seen the results but I have heard of people using hologen car headlights when they first came out.

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No offense intended, but think I'll stick to more traditional methods...

lol, nobody using mixed spectrum?

[video=youtube;Pr-JoqFVC5E]https://www.youtube.com/watch?v=Pr-JoqFVC5E[/video]

adding blue, or running mh/hps simultaneously effects the way the plant grows, less stretch and shorter petioles. yield is comparable, i found that there's no advantage/disadvantage. i ended up just running blue in veg for denser starts and hps for flower.

What about using ceramic metal halides? kitehigh swore by them and he had some damn good grows

kinetic said:

What about using ceramic metal halides? kitehigh swore by them and he had some damn good grows

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Anything from KH is gold, wish he was still with us.

Lemme dig around his old threads, not only was his UVB research helpful... but those reptile bulbs have an added benefit beyond producing more trichomes.

They work really well for germinating seeds.

Sunbiz1 said:

Anything from KH is gold, wish he was still with us.

Lemme dig around his old threads, not only was his UVB research helpful... but those reptile bulbs have an added benefit beyond producing more trichomes.

They work really well for germinating seeds.

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I germ in a coco pellet in a dome on a heat pad under a t5. My tomatoes sprouted in 12 hours a few days ago. I've never had cannabis take more than 3 days with that method. It works for me, and that's what makes me happy! I have to upgrade my hps bulb, my last grow showed signs that it is time. I'm pretty sure I'm grabbing a ceramic m.h. I like the idea of one bulb through the whole process.

kinetic said:

I germ in a coco pellet in a dome on a heat pad under a t5. My tomatoes sprouted in 12 hours a few days ago. I've never had cannabis take more than 3 days with that method. It works for me, and that's what makes me happy! I have to upgrade my hps bulb, my last grow showed signs that it is time. I'm pretty sure I'm grabbing a ceramic m.h. I like the idea of one bulb through the whole process.

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So here I am researching CMH bulbs, and look what popped up...lol

https://www.rollitup.org/indoor-growing/474019-ceramic-metal-halide-vs-hps.html

I flower under a mixed/dual spectrum. I use 2,000 watts of HPS overhead lighting and a little over 300 watts of 6500K florescent side lighting. I always get good results and good solid lower buds from the side lighting.

I've been starting my flower with a standard 600w MH and switching to HPS around week 2. I also run 5 minute bursts of UVB bulbs on their own timer and CFL's for side lighting. I'll also say that I've run a couple autos under my T5's only and had amazing results.
'

Huel Perkins said:

I flower under a mixed/dual spectrum. I use 2,000 watts of HPS overhead lighting and a little over 300 watts of 6500K florescent side lighting. I always get good results and good solid lower buds from the side lighting.

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Ditto here, in the end decided to switch 600 MH to HPS...then surrounded perimeter with additional 400W of 6500K. In addition there is also an extra 300W of merc vapor UVB.

Not as powerful as your set-up, but I only flower 4-5 plants.

VibRooter said:

I've been starting my flower with a standard 600w MH and switching to HPS around week 2. I also run 5 minute bursts of UVB bulbs on their own timer and CFL's for side lighting. I'll also say that I've run a couple autos under my T5's only and had amazing results.
'

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Why only 5 minute bursts on the UV/B?.

Everyone I've seen using UVB, run them on a separate timer. It's been so long since I did research, I forget exactly why, but basically less is more with them. in a 12 hour lights on period, the first 2 hours have no uvb, on the third and fourth hour they run for 5 mins, on the fifth hour 10 mins, sixth and seventh hour 15 mins, eighth hour 10 mins, ninth and tenth hour 5 mins, last two hours off. This cycle provides a more "natural" exposure to uvb rays, that plants would see in a place like Afghanastan, where uvb's are high. It also allows the grower time to work in the garden without being exposed to the harmful effects of uvb rays. Sorry I don't have a more exact answer of why, it has been a while, but the information is out there. I am a big fan of dual/multi spectrum lights in the grow room and have had great results.