Fonzarelli
Active Member
I've been doing multiple, multiple tests for the last few months with about 10 different T5 fixtures, LEDs and other light sources to understand what the different wavelengths do for cannabis strains. The tests are not done(probably never will be), but I've been able to at least come up with a few solid answers since there is so little information out there that is specifically designed around the herb.
First off, it is possible to grow really really good meds using only blue 460nm and red 660nm wavelengths. It just doesn't work for every strain. The ratios I have found to work the best(Weezard would agree) 3:1 for Veg, or 2:1 for shorter internode spacing, and 5:1 for flower, or 4:1 for shorter internode spacing.
I believe UVb light can be helpful for terpene production in the last few weeks of budding to increase flavor, smell, potency, but are useless anytime before the last 3 weeks of flower. This goes for any light wave lower than 450nm. Also, it has been found that 450nm will increase terpene/thc production as it is close to the deep blue wavelength. So it really is not necessary to add UVb into your grow. Your eyes will thank me.
I have found that different strains react very differently to the color of the overall blend of light source. This information has been backed up by others and is tried and true:
Sativa's prefer more blue light throughout the veg cycle and into the flower cycle. They can handle an increase of blue light without presenting any kind of weird growth issues, such as mutated twisted leaves, or irregular growth patterns.
Indica's prefer the red side of the spectrum. I found my Indica's to be very overly sensitive to blue wavelengths when used in a high ratio. The abundance of blue light will cause irregular growth patterns and will decrease yield dramatically if not corrected. They can also handle more red during flowering without getting over driven by the deeper red wavelengths.
There are a lot of misconceptions on the internet about the proper spectrum. The charts for photosynthesis and light absorption are based on Algae and the pigments and chemicals themselves within the plant. Trying to use the information for cannabis can get a little sketchy at times.
I have found it to be true that 630nm light can be nicely substituted for 660nm during the veg cycle. Although it is not as rapidly absorbed as the deeper red, it still has plenty of red energy that the plants use in abundance. I would at least try to keep a little 660nm in your light spectrum during the veg cycle. Your plants will thank you later. Having 630nm light in your spectrum throughout the whole growth cycle can be useful if you have and abundance of deep red light. The 630nm wavelength will balance out an over-abundance of 660nm wavelength. If there is more 660nm light than the plants can handle, photosynthesis will shut down and your plants will take on a phosphorus lockout look. Leaves get thick, turn yellow and claw. Growth slows and stems become purple. This is easily reversed by backing the red wavelengths off your spectrum a little. Also, it can be fixed by raising your lights.
Although many still disagree, 550nm green wavelengths can be helpful for some cannabis strains. When light irradiation is high(much red spectrum) the green will help the plants absorb the red wavelengths more efficiently. I think this is similar to how the 630nm wavelength helps to balance out the 660nm and slightly higher wavelengths. I've heard some people call the 550nm "the catalyst" of spectrum.
The 730nm wavelength has been known for some time to help generate Pfr more rapidly when in the flower cycle. Having 730nm in your light source during flower will speed up the budding process and assist with calyx production and growth rate. It has also been known for some time that in combination with deep red(660-680) will increase growth speed 2 fold.
T5 High Output Floro's:
There are a few German manufacturer's and a few U.S. ones that have been making T5 colored tubes for the aquarium industry for quite some time. The Sylvania Gro-Lux T5 is one good example. When properly blended, the floro tubes can achieve very closely to what the most latest LED technology has done. By increasing the wavelengths highly absorbed by cannabis plants, growth, health and quality are all increased as well as a huge power savings for you. The only drawback to the T5's are the lack of penetration since it is not a focused light beam. Reflectors can help some, but LEDs still have the upper hand.
LEDs:
As newer technology is being released in the LED world, we are seeing higher powered LEDs, dense matrix arrays, and an increase in overall efficiency. This is good. If you want to grow tall bushes and trees, the 10w LEDs are the ticket. If you are into building your own LED fixture then this thread is for you. Proper wavelength blending is of the utmost importance when dealing with so few High Power LEDs on a single panel.
This thread's focus will mainly be about light spectrum and other people's experiences with their own blends of wavelengths and not so much the "type" of light source. Keep the arguing about T5 vs. LED or HID to a minimum please. They are all fine sources of light. Light is light no matter what you may think.
Sit back, relax and you will see the light.
First off, it is possible to grow really really good meds using only blue 460nm and red 660nm wavelengths. It just doesn't work for every strain. The ratios I have found to work the best(Weezard would agree) 3:1 for Veg, or 2:1 for shorter internode spacing, and 5:1 for flower, or 4:1 for shorter internode spacing.
I believe UVb light can be helpful for terpene production in the last few weeks of budding to increase flavor, smell, potency, but are useless anytime before the last 3 weeks of flower. This goes for any light wave lower than 450nm. Also, it has been found that 450nm will increase terpene/thc production as it is close to the deep blue wavelength. So it really is not necessary to add UVb into your grow. Your eyes will thank me.
I have found that different strains react very differently to the color of the overall blend of light source. This information has been backed up by others and is tried and true:
Sativa's prefer more blue light throughout the veg cycle and into the flower cycle. They can handle an increase of blue light without presenting any kind of weird growth issues, such as mutated twisted leaves, or irregular growth patterns.
Indica's prefer the red side of the spectrum. I found my Indica's to be very overly sensitive to blue wavelengths when used in a high ratio. The abundance of blue light will cause irregular growth patterns and will decrease yield dramatically if not corrected. They can also handle more red during flowering without getting over driven by the deeper red wavelengths.
There are a lot of misconceptions on the internet about the proper spectrum. The charts for photosynthesis and light absorption are based on Algae and the pigments and chemicals themselves within the plant. Trying to use the information for cannabis can get a little sketchy at times.
I have found it to be true that 630nm light can be nicely substituted for 660nm during the veg cycle. Although it is not as rapidly absorbed as the deeper red, it still has plenty of red energy that the plants use in abundance. I would at least try to keep a little 660nm in your light spectrum during the veg cycle. Your plants will thank you later. Having 630nm light in your spectrum throughout the whole growth cycle can be useful if you have and abundance of deep red light. The 630nm wavelength will balance out an over-abundance of 660nm wavelength. If there is more 660nm light than the plants can handle, photosynthesis will shut down and your plants will take on a phosphorus lockout look. Leaves get thick, turn yellow and claw. Growth slows and stems become purple. This is easily reversed by backing the red wavelengths off your spectrum a little. Also, it can be fixed by raising your lights.
Although many still disagree, 550nm green wavelengths can be helpful for some cannabis strains. When light irradiation is high(much red spectrum) the green will help the plants absorb the red wavelengths more efficiently. I think this is similar to how the 630nm wavelength helps to balance out the 660nm and slightly higher wavelengths. I've heard some people call the 550nm "the catalyst" of spectrum.
The 730nm wavelength has been known for some time to help generate Pfr more rapidly when in the flower cycle. Having 730nm in your light source during flower will speed up the budding process and assist with calyx production and growth rate. It has also been known for some time that in combination with deep red(660-680) will increase growth speed 2 fold.
T5 High Output Floro's:
There are a few German manufacturer's and a few U.S. ones that have been making T5 colored tubes for the aquarium industry for quite some time. The Sylvania Gro-Lux T5 is one good example. When properly blended, the floro tubes can achieve very closely to what the most latest LED technology has done. By increasing the wavelengths highly absorbed by cannabis plants, growth, health and quality are all increased as well as a huge power savings for you. The only drawback to the T5's are the lack of penetration since it is not a focused light beam. Reflectors can help some, but LEDs still have the upper hand.
LEDs:
As newer technology is being released in the LED world, we are seeing higher powered LEDs, dense matrix arrays, and an increase in overall efficiency. This is good. If you want to grow tall bushes and trees, the 10w LEDs are the ticket. If you are into building your own LED fixture then this thread is for you. Proper wavelength blending is of the utmost importance when dealing with so few High Power LEDs on a single panel.
This thread's focus will mainly be about light spectrum and other people's experiences with their own blends of wavelengths and not so much the "type" of light source. Keep the arguing about T5 vs. LED or HID to a minimum please. They are all fine sources of light. Light is light no matter what you may think.
Sit back, relax and you will see the light.
I don't want this to come across as arrogance, but I would like to keep this type of talk to a minimum and focus on the topic at hand. 
