Effects of differing wavelengths of light on cana growth.

[Randalizer]

Hi PauloX,

Thanks for the compliments. I'm not a UV expert but I can share what I know. The 365 nanometers is the wavelength of radiation being emitted by those lamps. If you go back and skim these pages, you'll find a graph with the wavelengths of various radiations we are interested in, including visible light.

There are a few different types of UV available (UVA, UVB, etc) but not all of them are of interest to the cannabis grower. Indeed, I would say that UV light is one of the last things you should be concerned about. Getting other things like your environment air, medium and grow room security sorted first, is much more important.

If you are still interested you can check out this link (click here). It's probably the best topic here on how to use UV safely and effectively. UV can cause problems like skin cancer and clouding of the eye lens. The topic link above goes over these concerns and how to mitigate them. It also covers how much UV exposure to give your plants and how to find out what the UV exposure for different locations in the world is. So you can replicate the Portuguese sun. Somewhat.

Good Luck!

[PauloLx]

Hi Rand!

Thx for the fast reply.

After reading some dozens of threads and articles about the effect of UV lights while growing cannabis indoors i only know that i need to try it myself.

The relation between the trichomes maturation and UV rays.The impact of UV on plants left for seed.

The value of UV rays as fungicide and bactericide, ?is this a word? . The relation between the height of the plant and the UV light available.It all makes sense to me and i guess there´s no better way than the old experimental method

At the moment i got some available running set-ups, mine and from a couple of friends both in england and portugal, and our dream is to discover and maximize the potencial of each individual strain. It´s a long term project but we got all our blessed lifes

In order to maximize our efforts, each one focus in one specific direction, after doing two Sulphur burners and teaching my mates how to do it,i´m now looking into UV lights, what will come next?!?!

Thx again for your help

[groovelick]

Ok leaves are green because they reflex green light I know from your diarys rand that you have green flours for night work cause the plants dont in effect see the light. I like the idea of them....but if your growing a purple strain that deveolps purple leaves would this render them ineffectual as purple leaves would absorb some of the green light. ?

[Blayz'd]

Not sure how I missed this thread man. Looks quite enlightening. Pun intended.

I have a quick question though before I read more. I just read that green light has no effect on the plant and that the plant is blind to this spectrum. Yet it said that a plant grown solely in green light will be weak and small. If this is the case, surely it does use that light. Otherwise how would it grow at all, even if it's growth is weak. To me this means that the plant must use green light if it responds to it in any way. Or am I missing something? I'm not saying it's any good for growing with. I'm just wondering if it's true that green light has no effect.

[Randalizer]

.but if your growing a purple strain that deveolps purple leaves would this render them ineffectual as purple leaves would absorb some of the green light. ?

I'm just wondering if it's true that green light has no effect.

Anything is possible it seems. I did mention at the beginning of this topic (and on a few green light as work light topics) that some plant reactions to certain wavelengths would most likely be strain specific.

So far, every strain I've grown (6-8 but spread over 7 years or so of growing) has not reacted in any noticeable way to green light left on for 12 hours at night

Edited December 15, 2009 by Randalizer

[Randalizer]

I forgot to mention the obvious. A green light may be giving off more than just green light.

[weedfiend88]

finally read this whole thread (and al the related threads linked to it upto page 3is) last nite but couldnt really think of much to add to it but now I have. having been lookin for a 600w halide bulb but not seen a whole lot til I saw the sunpulse digi halide bulbs and the fact you can choose the colour of the light (degrees kelvin).

If i was adding a 600w halide lamp for a flowering room (for quality of cannabis not luminous efficiency), surely the 6400k would be of most use for that purpose? I think I remember reading plants only absorb light from 3000k-6500k (different sources disclose slightly diferent figures but pretty much the same from what I was reading) and that 6500k is rather blueish. Anybody wish to confirm this? Then about my suspicions about 6500k bein about as far up the kelvin scale I should be wanting to go for quality of crop?

I think im right but thats no guarantee. just lookin at other bulbs an it sais they do a 10,000k, 14,000k and a 20,000k bulb but im unsure of their usefulness if they (plants) dont absorb light from this range(of colour of light...)?

This would be i'd hav to buy a digital ballast but i'd be willing to step forth (and PAY PAY PAY...) and try but only if sure I was buying a quality bit of kit. I remember people slating some, with others rating a particular model (think it was next gen. but not sure) but i'd rather look into it further once the above is confirmed.

edit to say: just looked at lumatek and saw a price of £160 for a 600w one of their digi ballasts from a 'local' shop. is this brand reasonable? can anybody beat the price tho? I dont mind too much if it does what it sais on the tin i.e. 20-30% improved lumin efficiency over standard magnetic coil whatever theyrecalleds (standard halide / hps ballasts) + no heat from ballast etc

Edited December 22, 2009 by weedfiend88

[Randalizer]

Hey weedfiend,

First off, I'm absolute crap when it comes to sussing out kelvin temperatures. Given how competitive the indoor grow shop market is where I live, I just trust (more or less) the sales folk to steer me in the right direction. I've shopped a few indoor grow shops and they are pretty consistent in what they sell. Maybe some day I'll be more bold but for now I like the results with the lamps I'm getting (mostly Hortilux Eye series).

I use Lumateks and Nextgen and both work well, 2 of my Lumateks are well over two years old and working well still. And I push them hard. However this is not the topic for ballasts. If you want that then click here.

[PauloLx]

Hi there Rand.

Here´s a little input related with my experiences with the Woods Glass CFLs and the UV rays

These 4 beauties, White Widow from a mum germed from a Nirvava seed in 2007 still going, are in 3,5lts pots with JohnInes3 and tap water :wink: My mate swears that the plants become crustier and darker under those black lamps. We are all excited with the smoke quality because my friend reckons that quantity wise it´s gonna be great

I hope the pic works...sorry for the lousy quality

Peace and Light in many waves

[Randalizer]

Nice! I'll have to look those lamps up. Who makes them? Do be sure to give us a smoke report, eh?

Edited January 12, 2010 by Randalizer

[PauloLx]

Hi Rand.

Here´s some pics of the tanned WhiteWidows

The smoke test is coming soon

[PauloLx]

Just one more tanned babz

[Randalizer]

From all reports I have seen, dual spectrum lamps are not as good as single spectrum lamps.

I think now would a good time to mention that I'm not an expert on lighting by any measure. I set up this topic as a way to make it easy for folks to share information on lighting.

Edited January 18, 2010 by Randalizer

[CheeseyRhino]

Hello people, this looks like a thread that will suit my questions.

Got a 400w ballast. Got a 400w MH and a 400HPS but have been looking at the Grolux Dual Spectrum 400w.

I'd always just done the veg under MH and flowering under HPS.

Q1: This thread makes me think I should do the first two and last one/two weeks of flower under MH. What do people think is the time to swap the bulbs?

Q2: How does a grolux bulb compare? Would it give good results if used from veg right through to harvest?

I've also got a 2x55w sunmate if that helps... what would people do with one sunmate and one 400w ballast? (Bulbs are cheap in the grand scheme of things)

(Sometimes from seed, sometimes clone.)

Cheers people. Look forward to any replies!

EDIT - Ah, quick re-read of the thread and single spectrums are prerfered to the lazy grolux option. Wicked.

So when to change bulbs, and would the sunmate help at any stages?

Edited January 18, 2010 by CheeseyRhino

[sky]

Not sure how I missed this thread man. Looks quite enlightening. Pun intended.

I have a quick question though before I read more. I just read that green light has no effect on the plant and that the plant is blind to this spectrum. Yet it said that a plant grown solely in green light will be weak and small. If this is the case, surely it does use that light. Otherwise how would it grow at all, even if it's growth is weak. To me this means that the plant must use green light if it responds to it in any way. Or am I missing something? I'm not saying it's any good for growing with. I'm just wondering if it's true that green light has no effect.

i think the green light thing is similar to the way outdoor plants don't hermie even when theres street lights and the moon. intensity i reckon a plant receiving the suns strong rays isn't affected by the weak light levels given by a street lamp down the road. plants arent using a lot of green light so its not strong enough to give any bad effects but just like the street lamp over there it may be enough to sustain a plant if its all the plant has ever seen (nothing more intense)

all imo