4 x 23w 6500k or 4 x 42 watt 2700k for veg. Which would you choose?

[ahnold]

Hi. So right now I'm vegging out 2 plants going on 2 weeks. I can't help but think the growth is a little slower. I did just transplant them though. The 42watters are really supposed to be for flowering but have been too lazy to go to the store and buy a pack of 6500k's. They look very healthy though and have not stretched at all under the 2700k lights.

Anyone with experience on this?

 

[ahnold]

http://imgur.com/7UiIVPw

 

[Pinworm]

More light = A happier plant.

 

[ahnold]

More light = A happier plant.

Gotchaaaaa

 

[losthespider]

Would definitely get the 6500k for vegging, And use the 2700k for flowering

 

[Ace Yonder]

I am by no means an expert (Hardly even a beginner) but based on my research CFLs of all color temps actually produce a wide range of spectrum. HIDs like HPS and MH produce very narrow bands of light so choosing a spectrum close to what the plant needs is very important. Since CFLs produce light of a much wider spectrum, the 2700K will still put out blue light for veg, and the 42 watt 2700k could put out as much light in blue specturm as a 23 watt 6500k. (Althought it is good to note that 6500k puts out more red light than 2700k puts out blue light, and I have read quite a bit of research suggesting that 6500K cfls add quite a bit of potency to the buds if used during flower in addition to 2700K (Due to the increased uvb they emit)). This link should show a little bit more what I mean, but in general CFLs are much wider spectrum than HIDs so I would go for the setup with more lumens as opposed to the one that's closer to the spectrum you want. http://www.jungleseeds.co.uk/contents/media/ecolightspectrum.jpg

 

[TonightYou]

I am by no means an expert (Hardly even a beginner) but based on my research CFLs of all color temps actually produce a wide range of spectrum. HIDs like HPS and MH produce very narrow bands of light so choosing a spectrum close to what the plant needs is very important. Since CFLs produce light of a much wider spectrum, the 2700K will still put out blue light for veg, and the 42 watt 2700k could put out as much light in blue specturm as a 23 watt 6500k. (Althought it is good to note that 6500k puts out more red light than 2700k puts out blue light, and I have read quite a bit of research suggesting that 6500K cfls add quite a bit of potency to the buds if used during flower in addition to 2700K (Due to the increased uvb they emit)). This link should show a little bit more what I mean, but in general CFLs are much wider spectrum than HIDs so I would go for the setup with more lumens as opposed to the one that's closer to the spectrum you want. http://www.jungleseeds.co.uk/contents/media/ecolightspectrum.jpg

I think you'll be hard pressed to find commercial compact fluorescent giving out any uvb. Really the benefit is from the increased light spectrum, not any uvb light being emitted. You need specialty bulbs such as reptile lights that specifically emit uvb light. Really is for the benefit of everyone and probably the plants (not that plants dont benefit, not arguing that ,just people and placements plus amounts, so many variables).

 

[Ace Yonder]

I think you'll be hard pressed to find commercial compact fluorescent giving out any uvb. Really the benefit is from the increased light spectrum, not any uvb light being emitted. You need specialty bulbs such as reptile lights that specifically emit uvb light. Really is for the benefit of everyone and probably the plants (not that plants dont benefit, not arguing that ,just people and placements plus amounts, so many variables).

Well I am not a chemist but this is the article/post I got my info from (And subsequent research I've done has backed up most of it) http://www.420magazine.com/forums/grow-lighting/111680-cfl-light-tutorial.html
For brevity's sake I will also quote the pertinent section."During the flowering phase of a plants life, Warm light is better utilized to increase the size of a plant's buds. As CFL growers we tend to pile up on 2700k bulbs to increase our yield. In most cases, growers assume that warm light not only grants us larger buds, but insures that those buds are of connoisseur quality as well. This is not to say that one can not achieve a very successful crop off of pure warm spectrum 2700k lighting. We see it all the time as members of the Grow Forum Internet community. But as CFL growers, almost all of us demand a higher efficiency for our dollar. So what does this mean? Clearly I'm trying to emphasize the necessity of cool lighting during the flowering phase of a plants life. But why? Well thats simple. As many of you may have heard or read before, Cool lighting (6500k) introduces a UVB spectrum that benefits the potency of the buds our plants are producing. " The writer's own experience allow for a more specific conclusion: If the UVB photon is missing from the light stream(a), or the intensity as expressed in µW/cm2 falls below a certain level(b), the phytochemical process will not be completely energized with only UVA photons which are more penetrating but less energetic, and the harvested resin spheres will have mostly precursor compounds and not fully realized THC(c).... Side Note: Reptile lighting found at pet stores is not ideal for UVB lighting. Yes they do emit a high % of UVB than regular CFLs but they output less light and emit over 12x more UVA light than UVB light which can harm your plant." (From the article I linked under the Importance of Mixed Lighting section)

 

[TonightYou]

Im not a chemist either my friend
This is quoted by a forum, no actual citations. A quick google search of any consumer brand light will display the lack of significant amounts of uvb. Its extremely minute, puts even less out in the bulb designs and distance from the plant.

Here's some good info.
http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/HomeBusinessandEntertainment/ucm116400.htm

 

[samsgrow]

I am currently flowering and vegging using only cfl's. For vegging I used a total of 18 23 watt mixed spec, went higher on the bright white. For flowering am doing the opposite Running 11 23 watt and 1 42 w Loving life plants are beautiful little bushes. the one furthest in flowering is 18" tall 18" wide with 8 fat colas go with the smaller watts and add bulbs as plant gets bigger. keep them close.

 

[Ace Yonder]

Two things in the article you sighted back up the idea that CFLs do indeed emit uvb. Under the "What is the wavelength range of the light radiation that is emitted by CFLs?" header we find "....In addition, typical CFLs emit a small amount of UVB (280-315 nm), UVA (315-400 nm) and infrared (> 700 nm) radiation."
and under the "How close can we safely get to an operating CFL?" Header we find the following:[h=4]"...However, a recent study from the United Kingdom Health Protection Agency has found that there are measureable levels of UV from single envelope CFLs when used at distances closer than 1 foot. As a precaution, it is recommended that these types of CFLs not be used at distances closer than 1 foot, for more than one hour per day."[/h]Granted it may not be enough UV to warrant a warning under normal lighting conditions, but we certainly keep our cfls within 1 foot of the plants for much longer than 1 hour a day.

 

[TonightYou]

True but we should also consider the impact of the bulb shapes (long U-shaped and the curly cfl shape) and the true output per meter squared. The only reasonable equipment for a grower to use to use if one is interested is reptile lights.

I thought about trying to add uvb lights as it is a cheap add on, so did my research, looked up others, but a few things came to mind. The first problem was the potential to ruin everything, andn the second being uvb destroys things, including myself.

The wiki article is a great primer to uvb and kinda gives you an idea of sources for uvb http://en.m.wikipedia.org/wiki/Ultraviolet

 

[Ace Yonder]

I think the original intent of the people recommending 6500k cfls for uvb is precisely because the levels of UV are present, but low. They are something you want in moderation, like micro nutrients. Pure uvb lights would be far too intense and would do more harm than good. Remember the idea is that the plant uses the trichomes to protect itself from its environment, including UV rays. So you want to have SOME present so that it triggers the defense response and creates more/denser trichomes. But you don't want to flood it with the thing it needs protection from, the reason it HAS a defensive reaction at low levels is because high levels can be very harmful. For that reason I would avoid pure uv bulbs, but rather pick something that is a closer mimic to the light spectrum of daylight, not just the damaging parts of it. Its the same reason you want a fan to give plants a breeze, but you're not gonna put a leaf blower on them for 12 hours a day. Every medicine is also a poison depending on the dosage.