Would this be theoretically possible?

Metal Halide on for 18/6 (or 24/0 even) during vegetation, and Red Grow LED's on 24/0.


Switch to Flower. Metal Halide on 12/12, Red Grow LED's on 18/6.

Here's some information on red light and flowering:

MARIJUANA OPTICS: An elaboration on the process that makes THC

"The photoperiodic response is controlled by phytochrome. "Phytochrome is a blue pigment in the leaves and seeds of plants and is found in 2 forms. One form is a blue form(Pfr), which absorbs red light, and the other is a blue-green form(Pr) that absorbs far-red light. Solar energy has 10X more red (660nm) than far-red (730nm) light causing the accumulation of Pfr." The first and last hour of a day's sunlight is mostly red light because of the scattering effect on blue light. "So at the onset of the dark period much of the phytochrome is in the Pfr form. However, Pfr is unstable and returns to phytochrome Pr in the dark." The red light in sunrise returns the Pr to the Pfr form. "Phytochrome Pfr is the active form and controls flowering and germination. It inhibits flowering of short-day plants (the long night period is required for the conversion of Pfr to Pr) and promotes flowering of long day plants."



"The plants use red and infrared light to regulate stem growth and flowering response. Plant cells produce a chemical called a phytochrome, which has two versions. One version, PR, is sensitive to red light (660 nm). Red light converts PR into PFR. PFR signals the plant to grow short stocky stems and also helps the plant grow into specific shapes. The plants also use red and infrared light to measure uninterrupted darkness. As far as plants are concerned in terms of flowering, if there's no red light, it's dark.

PFR is sensitive to infrared light (730 nm), which converts it into PR. When PR levels build to a critical amount, scientists hypothesize that a hormone called floragen becomes active and induces the plant to flower. The reason floragen is called hypothetical is that researchers can see its effects, but they haven't found it yet.

PFR reverts to PR naturally. For PFR to be present, it must be renewed continuously by the presence of red light. When plants are shaded, they get less of the needed red light. In the absence of red light, the PR version predominates and the stem stretches to reach the light. Lower side branches shaded by leaves from above have PR and grow longer until they reach the light. Then they modify their growth in the presence of PFR.

Outdoors during the day, there is more red light than infrared. However, at dawn and dusk the first and last light from the sun isn't the visible red of the rising or setting sun, but infrared, which is at the far end of the electromagnetic spectrum. The infrared converts the PFR to PR and the critical dark-time begins or ends its countdown.

This has too many implications for them all to be discussed here. For instance, it explains why plants grown under incandescent lamps stretch (more infrared than red light). The effects of the two spectrums can also be used in innovative indoor lighting programs."

I don't know but here's what will work:
MH 18/6 or 24/0 for veg
HPS 12/12 for flower

I'd appreciate only replies about the mentioned expirement, not copy and paste common knowledge

Just grow 18/6 for veg and 12/12 for flower why u tryin to get all technical n shit??

no worries - good luck!

i think if you do that the fact that your plants are still getting 18 hours of light it'll take them longer to flower & may not flower at all. but give it a shot and let us know how it goes.

How about you stay out of the thread, and never change how you grow?

I'll stay here, and try and get some real feedback, and see if this might actually be worth trying because I'm not afraid of change.

Kthx

Could be, but I know they prefer red spectrum for flowering and it has to do with converting something (sounds real tech huh lol)

I don't know the exact terms but something I had read suggested that you could do longer photo periods during flower if at the end you gave them a certain amount of the red spectrum to convert x to y. I gotta find what I read again =/


**EDIT*** I found a different link, the red light is needed to confert PR to PFR

and another:

MARIJUANA OPTICS: An elaboration on the process that makes THC

"The photoperiodic response is controlled by phytochrome. "Phytochrome is a blue pigment in the leaves and seeds of plants and is found in 2 forms. One form is a blue form(Pfr), which absorbs red light, and the other is a blue-green form(Pr) that absorbs far-red light. Solar energy has 10X more red (660nm) than far-red (730nm) light causing the accumulation of Pfr." The first and last hour of a day's sunlight is mostly red light because of the scattering effect on blue light. "So at the onset of the dark period much of the phytochrome is in the Pfr form. However, Pfr is unstable and returns to phytochrome Pr in the dark." The red light in sunrise returns the Pr to the Pfr form. "Phytochrome Pfr is the active form and controls flowering and germination. It inhibits flowering of short-day plants (the long night period is required for the conversion of Pfr to Pr) and promotes flowering of long day plants." "

When you switch your light cycle to 12/12 it tells the plant fall is coming and it is time to flower. By leaving on the led's the plants are still receiving 18 hours of light, it may not be enough to stop them from flowering but I think it will increase flowering time and my even lighten the yield.

This I know. It's more like, yes 2+2=4 but what other ways can we get 4?

The idea is to trick plants with certain spectrums to try to manipulate them to do what you want.

I'm really hoping someone with some insight into light spectrums and their effects could reply..... no offense to anyone but I have read what WORKS and that kinda copy/paste stuff is just not helpful at all with my question on using a certain spectrum light in this way (all you're talking about is the plant getting ANY light, if you know for a fact that it doesn't matter what spectrum from blue to far red then please elaborate on your response with details and explain why I cannot mess with the PR to PFR conversion by using light)

From what I've read if I got a strain that could be considered a long day plant rather than the typical cannabis plant which is short day, it could be possible to benefit the flowering with extra 660nm red, but if I can't get a strain that could qualify as long day it appears that the extra 660nm red would be bad, but a FAR read (700 something) could possibly be used in a benefitial way