[Gerardbutler79]

Wow pepe. You sure know your stuff lol tell us more!

Green Science: I'm glad you're running an experiment like this for others to learn from, however, CFL's like the ones I see in your pic won't suffice for proper UVB supplementation. Nor will ZooMed products or anything in that video pepe posted. Gonna shoot ya a pm.

[yesum]

I have Reptisun 5.0 and 10.0 27 watt cfls. I use a Solarmeter 6.2 which measures the uvb in our spectrum. 280 to 320 nm or whatever they are called.

The light is too intense at closer than 3 inches(700 or so uw) and falls off to non useful levels at more than around 10 inches from bulb.

You kinda need a meter which runs almost 200 clams. If you run the light I listed then just go by my advice if you want to save on a meter. 500 uw is the higher limit and 150 uw being the lower limit to get any effect.

I turn off the lights when working in the garden. At least wear uv blocking shades if you do not turn them off.

[GP73LPC]

interesting

[Pepe le skunk]

Originally Posted by Gerardbutler79

Wow pepe. You sure know your stuff lol tell us more!

Green Science: I'm glad you're running an experiment like this for others to learn from, however, CFL's like the ones I see in your pic won't suffice for proper UVB supplementation. Nor will ZooMed products or anything in that video pepe posted. Gonna shoot ya a pm.

Feel free to share your info. The meter Yesum uses is a good indicator of the power of UVB and his readings are correct.

Originally Posted by yesum

I have Reptisun 5.0 and 10.0 27 watt cfls. I use a Solarmeter 6.2 which measures the uvb in our spectrum. 280 to 320 nm or whatever they are called.

The light is too intense at closer than 3 inches(700 or so uw) and falls off to non useful levels at more than around 10 inches from bulb.

You kinda need a meter which runs almost 200 clams. If you run the light I listed then just go by my advice if you want to save on a meter. 500 uw is the higher limit and 150 uw being the lower limit to get any effect.

I turn off the lights when working in the garden. At least wear uv blocking shades if you do not turn them off.

Nice one Yesum. Have seen a few different tests including readings at noon in the tropics using the same meters. When you consider the UVB the plants receive in the final weeks the extra % of uvb is helpful even if it is between the 150 and 500 readings. The exposed buds will produce additional resin the plant is capable of producing with the extra wavelength of light.

Coverage and exposure to the nm (nanometer)wavelength of light at a high enough intensity is what I would consider most important and is why I rotate them every few days. Similar to feeding the bacteria in a soil food web molasses. If you follow the thinking that UVB will act as a catalyst in the production of THC.

[Pepe le skunk]

Here is another good link to bulb tests and the results concerning specific wavelenghts of uvb. 270-300 and 300-320nm.
Worth a read.
https://www.uvguide.co.uk/phototherapyphosphor-tests.htm

Here is a test from 2011 and 2012 from another grower.
https://www.icmag.com/ic/showthread.php?threadid=220433

[skunkfunk]

Interesting thread. I have in the past used UVB supplemental lighting and did not notice a difference. However by doing a proper side by side experiment like this with the good research being done we can find out how this turns out, good one.

Just to add that at high altitude cannabis is growing in a cooler climate. Last year I purposely flowered my crop in lower temperatures at 18C. They took longer to flower and the resin profile was excellent with a difference in potency to the same clones flowered at the usual temperature of about 24/25C ( these matured quicker by about 3 weeks ).

Maybe the temperature could be another variable to be considered.

Looking forward to seeing the results of this side by side experiment.

[forkup]

Great thread guys, the results should be very interesting. Thanks for the effort.

[Incognegro]

interested to see more

[Green_science]

UVB bulbs have arrived and been setup, I only took pics after setting 1 bulb up the other is placed in the same spot as the, except it's closer to us to keep things symmetrical, the photos are a little deceiving , the bulb does not even run half the lenght of the space, so half the plants are definitely not receiving any UVB supplementation

[Green_science]