from what i've heard (don't quote me on it) mh will give you bigger less dense buds, hps will give you smaller (relatively speaking) dense buds thats why some people use dual specturm bulbs
ok so the ONLY real information that hasnt been regurgitated here.... is the guy who says flower with HPS until the last 2-3 weeks then switch back to MH for increased taste/trichomes... over the HPS (HPS helps stretch larger bud/MH at the end will densen them up and create more trichomes.)
The sun emits the same spectrum of light year round,but as a season ends, so does weather, light time and a whole load of precipitation stuff. I believe its how the plant absorbs the spectrum of the light, not how the sun is changing spectrum..lol
I have a similar question, I bought a 1000w sunmaster Cool Deluxe MH Conversion Bulb, But I also have a 1000w Hortilux eye HPS which is definately more in the red spectrum by a 1000 miles, I wonder if the sunmaster would put out a better crop than the Sunmaster. I often heard about the seasons getting longer etc etc the sun is lower in the sky so the light is redder etc etc... what I don't understand is at the equator And correct me if I am wrong is not the sun always in the same position in the sky and 12 days are in perpituity. So that being said there are Sativa strains that grow pretty well there prolly evolved there, I wonder would a MH be sufficient?
The solar spectrum shift due to atmospheric filtering is large from early morning to mid-day. Seasonal spectral shift is nothing in comparison and has NOTHING to do with switching to HPS for flowering. I have covered this in detail on several occasions.
If the sun rises in the same place and sets in the same place everyday for eternity, then one would surmize the spectrum of light it recieves would not change if not for the weather, In summer in the northern hemisphere the sun at the solstice mimcs that of the equatorial regions, as winter approachs the sun travels lower in the horizon giving way to the effects of a perpetual sunrise. This is where the Red sunsets come from, however there are also red sunsets in equatorial regions but only during the late evening. The spectrum of light the plants use in the northern and southern hemisheres changes with the seasons. However not the case in equatorial regions. The HPs switch is to mimic the seasons, something the equatorial region doesn't experience as they always have 12 hours of light. So the question remains, if the sun at the equator remains the same seasonally why would i not flower with MH, maybe this is why Sativas flower longer, because they get more blue spectrum and have evolved to best harness it? I don't know maybe I am thinking to far into it? Pretty sure there is something to it. So in closing SWAMI i challenge your Idea, I believe Seasonal spectral shift has more influence the further north or south you travel. I believe the daily sunrise and sunset has less to do with the HPS switch. However you would be correct if you lived in the requator and the northern andf southern hemisphere had not been discovered yet.
Its more about the heat in Kelvin than Lumens. Lumens measures light visible to humans, Plants do not see light in Lumens they see it in Kelvin, not unlike our friend the Honey bee who see in the Infrared spectrums, thats whay flowers grow as they do light colours to attract bees, So plants are triggered by the same spectrum of light that tells the bees to polinate, everyone with a 8th grade education knows that bees need pollen to make honey for there young and in gathering it inadvertantly pollinating the flowers they visit completeing the plants reproductive cycle and the final product is a seed and another year of plants. So the Red spectrum PAR, plays a huge roll in providing the plant with the signal to reproduce.
Not even close. Not one person has ever shown this amazing seasonal shift. I honestly don't know why I bother as I have debunked a dozen cannabis myths with science and yet they still persist. Young plants need more blue than HPS provides thus MH is used. HPS has much better efficacy than MH thus is used in flowering where blue light is not as critical. That's it. Plant do NOT need more red in flowering nor does it have anything to do with the season. If HPS bulbs can be made with suffiicient blue (at least 10% vs. about 3-4%), then no switch would ever be necessary. The sun, CMH, balanced LEDs and warm fluorescents may be used for the entire grow without switching.
Okay you seem to claim you have debunked my question...? Alright...? I agree with you. I am not sure how to respond. It is a scientific fact that Plants tend to respond in a linear fashion to PAR, not Lumens or Watts. not sure what you've debunked here but perhaps if you have you should write a paper and have it published, from what I can tell plants photosynthisize, and chlorophyll is green, and it is green because it absorbs all other spectrums that are not green, including "blue" and "red". Chlorophyll, the most abundant plant pigment, is most efficient in capturing red and blue light. Go figure... An exception to the predominance of chlorophyll is autumn, when chlorophyll is degraded (because it contains Nitrogen and Magnesium) but the accessory pigments are not (because they only contain Carbon, Hydrogen and Oxygen) and remain in the leaf producing red, yellow and orange leaves. Yay it's fall. But only in the northern and southern hemispheres because the equator that have alot of native Sativas Skip those seasons. I can only imagine with your logic you must have grown up around the equator and not experienced spring or fall.
. I honestly don't know why I bother as I have debunked a dozen cannabis myths with science and yet they still persist. They persist perhaps because your debunking method is driven by Ego instead of a solid mature intelligence that can only be achieved through years of study such as highschool and college or perhaps even university. Come on down with the rest of us here, you will find it is much less stressful down here than up there with that massive Brain.
However, I must admit I have a friend who's name is Manish, from Pakistan, he is Hindu, he refers to his religious masters as Swami, so I would bet that your heritage resides in Pakistan, right smack dab on the equator, which would explain your understanding of the seasons, because you don't have the ones that produce the red Par. Ah... Which would explain why you don't seem to think seasons have anything to do with the HPS mimicing the seasons, because you don't have that season, I understand now. Open your mind swami. There is much to learn about mother nature. And even more we will never understand.
There seems to have been a de-railment in this discussion, so I'll skip back to the original question. WGG, there are a few options. My 1st choice would be to get a 250 or 400W HPS and add it right along with your MH, that way you'll be pushing a lot more light and have a bigger, better harvet than just using one. If your space will not allow this, you can get a conversion bulb for your MH for about 80 bucks. You lose a little kick, since the MH to HPS conversion bulb pulls 360 watts and delivers 45,000 lumens initially. Another economical option for a single lamp grow is simply to get the 3000K, 400 watt MH compact bulb. At 39,000 lumens it's pretty decent for flowering. I've pulled up to 6.75oz dried and manicured from seed with only 2 plants under a 3000K, 400W MH. The calyx development won't be quite what you'd get from an HPS, but many say the trichome development is superior when you have more blue during flowering and I agree. If you have the area though, I would flower with both a 400w MH and 400HPS side by side and rotate the plants every few days.
Nice made up story, just like your other made up 'facts'. I have taken college level physics, so know tons about light and have done much study on botany and horticulture. You can jabber all you want and yet, like all the others, you will not be able to produce a single scientific article on seasonal color shift. The end.
One certainly does not need to go to college to learn about light as it applies to growing. As it seems that you think your the only one here who has an education and holds the key to the secret that is mother nature, I am inclined to read more of your posts and debunkings. Perhaps you can point me to you online cannabis forum debunking exploits so I may gleen them and be enlightened.
your right you will get more weight from running the MH light however the weight comes from the plant responding to the bluer PAR and growing more leaf in response, thats why the Bluer MH is used to veg. The MH and HPS combo is used more in Pure Sativa strains to bulk up the Wispy Buds and get more weight for sale. The weight however like I mentioned is more leaf. and that is for the benefit of sale by weight. Anyone who does the combo with Indicas is wasting time and energy, Red par signals the plant to produce more essential oils and resin etc, the blue par will only steal energy from bud production to produce more leaf. Lumens per watt is the measurment of light visible only to humans, it is the par or Photosynthetically active radiation, often abbreviated PAR, designates the spectral range wave band of solar radiation from 400 to 700 nanometers that Cannabis uses during its life cycle. So find the bulb with the best par rating in the blue part of the spectrum to simulate mid summer in the northern and southern hemispheres, and to simulate the end of summer and the approach of fall use an HPS with red Par on a shortened light cycle of twelve twelve, this simulates the shortend days of fall and signals the plant to seed before the onset of winter and freezing temperatures, red par helps produce more resin that makes the plant sticky which aids in the capture of pollen.