I see what your saying, but what is your control? How can you compare 2 things together that are measured differently? How many extra lumens do you give a plant before you decide that it is equal to the ammount of change in color spectrum? The way you are saying the test is being done. you're not adding color spectum by switching color lights, then how are you adding color spectrum without adding lumens?
Trichomes, THC and UVB light.....
- Thread starter tahoe58
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tahoe58
Well-Known Member
I agree with you this is not as simple as I am putting forward. The fact that MH of the same wattage puts out less lumens than a similar HPS....and the fact that the plant veges better under MH and flowers better under HPS ...... so this does make it more complex than I am presenting.
I believe that by measuring solely the differential in growth...i.e., as measured by say dry weight from each plant.....then you effectively remove the uncertainty and the need for a control.
In my example I take two plants the same and grow them under two lights (both MH or both HPS) but one is 250W and the other is 600W and get a dry weight differential between the production from each plant. Say one plant yeilded 2.5oz and the other 3.25oz.
Then two of the same plants again, and grow under the same wattage bulb (say 400W), and one is red spectrum and the other is blue spectrum. the dry weight differential again measured from final production.
I believe the the dry weight differential coming from the increased light intensity would be a greater number than the differential measured from the plants grown under red versus blue spectral bulbs. So, all else being equal, icreasing the intensity under which you grow will bring a bigger improvement in yeild than a smiple change from red to blue or vice versa.
I believe that by measuring solely the differential in growth...i.e., as measured by say dry weight from each plant.....then you effectively remove the uncertainty and the need for a control.
In my example I take two plants the same and grow them under two lights (both MH or both HPS) but one is 250W and the other is 600W and get a dry weight differential between the production from each plant. Say one plant yeilded 2.5oz and the other 3.25oz.
Then two of the same plants again, and grow under the same wattage bulb (say 400W), and one is red spectrum and the other is blue spectrum. the dry weight differential again measured from final production.
I believe the the dry weight differential coming from the increased light intensity would be a greater number than the differential measured from the plants grown under red versus blue spectral bulbs. So, all else being equal, icreasing the intensity under which you grow will bring a bigger improvement in yeild than a smiple change from red to blue or vice versa.
psyclone
Well-Known Member
People........Why Can't We all Just.............Get Along.....?
Actually the point in question for me is that more power (wattage) does not, these days, mean more light. There are as we all know low wattage LED lights available which have a tremendous light output, a three lamp full spectrum inc UVB array using I think about 55watts and with little tell tale heat waste.
I will constantly try to increase my light intensity (broad spectrum) while reducing the overall power consumed.
Actually the point in question for me is that more power (wattage) does not, these days, mean more light. There are as we all know low wattage LED lights available which have a tremendous light output, a three lamp full spectrum inc UVB array using I think about 55watts and with little tell tale heat waste.
I will constantly try to increase my light intensity (broad spectrum) while reducing the overall power consumed.
tahoe58
Well-Known Member
totally agree....this is absoutley the case. With LEDs the highest lumen output I have seen is like 900 lumens....but you can certainly make up boards of broad spectrum and have a very cool grow system. I have been watching this for some time. I have a colleague that is doing a combined MH/HPS and LED setup right now....all very secret about it though.....cool experiments!
tahoe58
Well-Known Member
I found an interesting book, Hydroponics Indoor Horticulture - has a really good section on light. in this he talksabout the depreciation of light intensity over distance - if starting with one lumen at 1 ft. from source becomes 1/4 at 2ft., 1/8 at 3ft., and 1/16 at 4 ft. In his examples - 1000W HPS with 140,000lumens at 1 ft., is at 4ft is less than 10,000lumens.
He goes on to say that in a room with an eight foot ceiling, and the light not suspended, the light hitting the floor is 1/64th the original intensity, and in his example at 100W HPS with 12,000 lumens eight feet away from your plant will give you the same intensity as being 1 ft. away from an incandescent blub at the floor level.
He goes on to say that in a room with an eight foot ceiling, and the light not suspended, the light hitting the floor is 1/64th the original intensity, and in his example at 100W HPS with 12,000 lumens eight feet away from your plant will give you the same intensity as being 1 ft. away from an incandescent blub at the floor level.
These are the LED bulbs I have from gro-tek. LED Grow Lights Gro-Tek GroTec HID Hydroponic light Fluorescent leds Growing Metal halide MH growing indoorS indoors Ultraviolet Infrared light emitting diodes supposed to be top of the line, but i always just say "high end", cuz you never know. The thing about LEDs and the reason I buy so many (2044) is because they max out at out 720NM on the red end of the color spectrum. There is no other light that can do that. Even the new advanced T5s peak at only 635NM, which is higher than HPS by the way. On my next grow, which will be my first ONLINE grow ever by the way, I will be using a MH bulb the entire grow. Rather than use an HPS bulb for flowering I am going to try it with a MH for UVB, as well as a bud hardner (humboldt's gravity) to get the dense buds HPS would provide. The red end of the color spectrum that my plant loves so much during the flower cycle will be supplamented by LEDs. What do you think Tahoe? would that get me the UVB I need?
tahoe58
Well-Known Member
I like you thoughts about the red spectrum stuff from the LEDs. I think your setup should prove to be quite productive. I would have to go looking for one of the original posts in this thread.....but essentially it talked about from a "quality" perspective....an MH bulb actually had better results that using the HPS. I have come to believe that the flood towards HPS has been fdriven b y the spped and yeild objectives of commercial growers. It has been stated that MH does have some UVB and this is also one of the reasons for the better results.
As I have stated....my intent is to at some point in the near future go with MH in vege and in flower - 2 MH (100W) and 1 HPS (250W) and supplemented with UVB (MegaRay 160W) or when the UVB LEDs are ready then those.....but I believe you are on the same or similar train of thought....
As I have stated....my intent is to at some point in the near future go with MH in vege and in flower - 2 MH (100W) and 1 HPS (250W) and supplemented with UVB (MegaRay 160W) or when the UVB LEDs are ready then those.....but I believe you are on the same or similar train of thought....
Thats a good find tahoe. It is important to get your lights as close as possable. Not to loose any lumens that the plant could be using. Thats why even when growing in large rooms people are using in-line coolable light reflectors.lights are able to get much closer to the plant when heat is not a problem.
Some people think that the use of high pressure sodium (HPS) light as a sole source of lighting has resulted in unconscious selection for lower THC parents during breeding. This theory is based on the assumption that ultraviolet light is a large causal factor in the plants production of THC. As HPS lights produce little in the way of UV, the lower potency plants could look the most vigorous in early selections (before flowering) as they would have a genetic advantage over high THC plants (less wasted energy).
Anyone that has ever seen a mixed light garden can testify that the healthiest, most crystallized buds occur where the two spectrums overlap.As metal halide bulbs emit a fair amount of UV while HPS emit almost none. Most growers employing halides in conjunction with HPS do so at a 2:1 HPS:halide ratio. Many growers, especially those restricted to one light, have been having good success using one of the new enhanced metal halide bulbs such as Sunmaster(what I use), which have a more balanced spectrum than either sodium or regular halide alone.
Also,I have heard but not tested the theory that Quartz glass will allow the most uvb to go through. Although manufacturers don't put them on reflector hoods.
Anyone that has ever seen a mixed light garden can testify that the healthiest, most crystallized buds occur where the two spectrums overlap.As metal halide bulbs emit a fair amount of UV while HPS emit almost none. Most growers employing halides in conjunction with HPS do so at a 2:1 HPS:halide ratio. Many growers, especially those restricted to one light, have been having good success using one of the new enhanced metal halide bulbs such as Sunmaster(what I use), which have a more balanced spectrum than either sodium or regular halide alone.
Also,I have heard but not tested the theory that Quartz glass will allow the most uvb to go through. Although manufacturers don't put them on reflector hoods.
Lol. I'd like to think that MH bulbs, not to mention ballasts have come a LONG way since the 1980's.Ah, yes, Metal Halides used all the way through, including flowering.
Just like 25 years ago, when M/H was all we had.
Smoke2Live420
New Member
what makes that light different from any other light?
psyclone
Well-Known Member
LED Grow Lights - Range Check this out for trick lighting boys.
You misoverstood what I wrote. Its not type of light that concerns me, its the fact that I would be introducing my plant to irregular light cycles. I don't know this to be true, it is only a concern of mine. Is a UVB light strong enouph to confuse the plant (during flowering)into thinking it has missed its chance to reproduce? And if so will the plant in one last ditch effort to continue its species, begin to produce seeds?
skunkushybrid
New Member
If the light isn't strong enough to affect the plant then it isn't worth using.
sorry did i say affect? I meant confuse