Effects of differing wavelengths of light on cana growth. Will start with MH/HPS but branching into other wavelengths is welcome
Posted 28 December 2011 - 11:11 PM
Posted 29 December 2011 - 06:13 PM
Cheers groovelick. After a bit more reading on here, think I'm just gonna ditch the UVB option and just stick with the MH for last couple of weeks of flowering - what u think? Does UVB really give you a noticeable difference in quality of smoke?
Posted 28 September 2012 - 03:34 PM
Great infos collected here. folks! It is mostly in line and confirming what I have researched or experienced. Good to break up the hps myths and the notion that only red in flowering is the only way to go - after all, the sun offers all the wavelengths through the whole life cycle - it doesn't shut off the blue wavelengths just because certain plants are flowering ;-)
Blue wavelengths during flowering will fill-out and fatten up the stretched calyxes from hps. The morning-noon-evening / red-blue-red routine is a good simple scheme to imitate nature. Can save energy too, if full-blast is only at high-noon. Plants in nature don't experience, instant-on full blast from dawn to full blast with instant cutoff at nightfall either, but rather a fade into and fade out off peak lumens. For those wishing to save energy and cut costs, it is helpful to think about light-cycle as one thing and peak illumination as another, entirely seperate issue.
Posted 02 December 2012 - 02:39 PM
this is a post from GreenFloyd that i feel is accurate, has helped me with my whole understanding of spectrums. ive decided to go for a gavita light system now. check it out if u havent already seems promising
"It's the UV-B from MH that increase potency in both, Indica and Sativa's.
Research by Ed Rosenthal stated something similar to Ot1 regarding the Blue spectrum for MH.
He states that it is the Far-Red light that causes stretching and Sodium bulbs don't emit that wavelength.
"MH were originally promoted as the light to use during the vegetative stage of the plants growth, before the plant is forced to flower.
But now it is generally recognized that plants grow just as well vegetatively under a sodium as under MH.
Since plants need red spectrum for photosynthesis, it's absence is felt when using MH." Ed
HPS (sodium) lamps support fast growth during veg and flowering stages. They need no supplementing during any stage of growth." Ed
"Cannabis is a high energy plant, some schools think the thc/resin glands developed to protect against intense shortwave light.
Halides provide that to some extent, but don’t compare to high altitude sunlight in the tropics." OT1
The only real benefit it appears from a MH is when used with or in-place of a sodium during the final two weeks of flowering. The UV-B from the MH greatly increases THC potency.
IF you only have one reflector, I would stick with the sodium as during the last two weeks your buds are still packing on the weight and density which the sodiums excel in.
If you can, add a UV-B reptile lamp in there during the last two weeks.
If you had two reflectors, stick a MH in one for the last two weeks."