groovelick Posted December 28, 2011 Share Posted December 28, 2011 If using uvb remember to cover your arms and cover your eyes when working with the girls or just turn the uvb off 1 Link to comment Share on other sites More sharing options...
silverhazey Posted December 29, 2011 Share Posted December 29, 2011 If using uvb remember to cover your arms and cover your eyes when working with the girls or just turn the uvb off 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? Link to comment Share on other sites More sharing options...
Ganjasattva Posted September 28, 2012 Share Posted September 28, 2012 There are some nice, compact and easy to add super-twist cfl reptile lights with the standard E27 screw-in base, "Repti-Glow" with various gradients of UVB. 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. Link to comment Share on other sites More sharing options...
Fungai Posted December 2, 2012 Share Posted December 2, 2012 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? 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 GreenFloyd stated. "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." Link to comment Share on other sites More sharing options...
turtlehood Posted January 3, 2014 Share Posted January 3, 2014 Possibly a stupid question, but has anyone tried light filters, or, say, putting blue cellophane on their tent walls during veg and red during flower? would that even make a difference? I used just a hps for veg and flower, never thought to try blue walls during the growing stage. Link to comment Share on other sites More sharing options...
highgrower Posted January 3, 2014 Share Posted January 3, 2014 (edited) Light doesnt work like that. If there isnt blue in the light the filter wont be able to add it. Do a google for: newton two prism experiment Edited January 3, 2014 by highgrower 1 Link to comment Share on other sites More sharing options...
stonerwizard Posted April 27, 2014 Share Posted April 27, 2014 Great thread. I am an led grower but I plan to add some uvb during the last few weeks of flower. There are so many LED Vs HID threads here and every other board but I like the idea of a combined LED and HPS, best of both worlds The wave length and low heat of high output LED panel plus the heat (I'm thinking bare bulb so not too much) and the red high lumen output of HPS. Could be an idea for people who want more light without too much heat Just a stoned idea Wizard Link to comment Share on other sites More sharing options...
zero Posted April 16, 2016 Share Posted April 16, 2016 Great thread. I am an led grower but I plan to add some uvb during the last few weeks of flower. There are so many LED Vs HID threads here and every other board but I like the idea of a combined LED and HPS, best of both worlds The wave length and low heat of high output LED panel plus the heat (I'm thinking bare bulb so not too much) and the red high lumen output of HPS. Could be an idea for people who want more light without too much heat Just a stoned idea Wizard I live close to some commercial greenhouses (tomatoes) , they use hps at the top and LED's on the lower plants ...... seems to produce hefty tomatoes Link to comment Share on other sites More sharing options...
OldBeardo Posted September 9, 2016 Share Posted September 9, 2016 Personally I would avoid UVB like the plague. It can improve THC yeild in certain strains but at the expense of metabolising all of the CBD. By using a lot of UVB you could turn an 18%THC 10%CBD plant into a 19%THC 0%CBD plant, but I'm not sure you would really want to. 1 Link to comment Share on other sites More sharing options...
Embryo Posted September 9, 2016 Share Posted September 9, 2016 Do you have a source for that info @@OldBeardo please? 3 Link to comment Share on other sites More sharing options...
MyDisplayName2000 Posted February 2, 2019 Share Posted February 2, 2019 On 03/01/2014 at 10:09 PM, turtlehood said: Possibly a stupid question, but has anyone tried light filters, or, say, putting blue cellophane on their tent walls during veg and red during flower? would that even make a difference? I used just a hps for veg and flower, never thought to try blue walls during the growing stage. No question is stupid if you do not know the answer. The blue and red wavelengths of light are not visible to the human eye. We just see light. Walls need to be reflective so light will bounce off them and not heat them up. So no, leave that paintbrush alone. Unless its matt white paint. The original growers reflective surface. Link to comment Share on other sites More sharing options...
Kickstand Posted May 2, 2019 Share Posted May 2, 2019 Some good info in this vid on how light spectrum effects weed Link to comment Share on other sites More sharing options...
murphyblue Posted December 14, 2019 Share Posted December 14, 2019 dunno if it made a difference or not but i have 3 different spectrum's in my room a 6500k floodlight 50w led just a (cob really)a large bozily cheap light draws about 75w and just checked and its 2600k and some cheap purple bulbs above them point being my last grow stayed green as hell right up till chop tric's were milky and amber,they were on just water for 2 weeks but no yellowing like ive seen in other grows. could it have been the mixed up lights i dunno but it was the only thing i could think of other than it was in the plants genes. Link to comment Share on other sites More sharing options...
Kickstand Posted December 14, 2019 Share Posted December 14, 2019 23 minutes ago, murphyblue said: dunno if it made a difference or not but i have 3 different spectrum's in my room a 6500k floodlight 50w led just a (cob really)a large bozily cheap light draws about 75w and just checked and its 2600k and some cheap purple bulbs above them point being my last grow stayed green as hell right up till chop tric's were milky and amber,they were on just water for 2 weeks but no yellowing like ive seen in other grows. could it have been the mixed up lights i dunno but it was the only thing i could think of other than it was in the plants genes. Probably your feeding schedule than anything else Link to comment Share on other sites More sharing options...
Goohfy Posted December 14, 2021 Share Posted December 14, 2021 Mh veg then hps with uvb for the last 3 weeks.Must say getting the place to hang the uv tube fucked me off with it being so much higher in the groom.but that works a treat and I have messed around with different light ratios.peace goohfy. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now