UV Suppliment Lighting

drinkoldcoke

Active Member
Very true.
But enough have some faith in UV supplimentation, to keep this thread going. What would be a concern for me ,personally, is pushing vague information out to bolster the case for use. There is potential for harm. (this is not the far red thread where someone blithely tells a newcomer to run for 15 mins and the guy ends up with a tent or room of stretched out plants from excess far red.)

If I have a cutting that is consistently testing 18%, but using some UV lighting product gives me a 4% increase on that.

18 x 0.04 = 0.72
0.72 +18 = 18.72

Result 18.72%. Worth it? And that potential percentage increase is going to vary by cultivar and the type and amount of lighting. Now what if you have some famous high thc varieties? Testing mid 20's? Wonder what the likelihood is of those getting an extra 20% on top? The devil is in the details.

Realistically outside our capabilities, to make statements without accurate measurement and repeatability. What we can do in this thread is read the research papers people have taken time to post. Read the posts giving details and examples. Use that information for a general starting point for levels of supplemental light.

Hopefully it will become easier when sensors become cheaper and more widely available. Then everyone can be on the same page.
The problem here is everyone is so worried about more THC and not enough about secondary metabolites, which IMO is much more important than 18 > 18.75. Don’t be so hard on UV, just go with, “less is more”.
 

Kassiopeija

Well-Known Member
There is a video on Youtube
A link would be nice

I understand that adding far red is useless without sufficient ps2 excitation.
Yes indeed, well PS2 + its antenna holds a great number of chlorophylls so given any PAR light present it'll always be thoroughly exzitated (in comparison to PS1) - except perhaps if one uses a fancy artificial light setup, like IR LED or incandescants with blends...

It's this way because the spit of H2O to gather free electrons happens in PS2. Without that, or selective PS1 exzitation, not much is happening, but it's difficult and some species - esp. bacteria - actually found a way to adapt to such a light setup. But not landplants...
 

drinkoldcoke

Active Member
A link would be nice


Yes indeed, well PS2 + its antenna holds a great number of chlorophylls so given any PAR light present it'll always be thoroughly exzitated (in comparison to PS1) - except perhaps if one uses a fancy artificial light setup, like IR LED or incandescants with blends...

It's this way because the spit of H2O to gather free electrons happens in PS2. Without that, or selective PS1 exzitation, not much is happening, but it's difficult and some species - esp. bacteria - actually found a way to adapt to such a light setup. But not landplants...
I found you a link because my favorite color is green and who wouldn't like a green haired lady for an avatar ? Below is the video where the UV was mentioned. Also, does 18 Samsung strips on an 18 x 24 substrate count as fancy ?

 
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Kassiopeija

Well-Known Member
I found you a link because my favorite color is green and who wouldn't like a green haired lady for an avatar ? Below is the video where the UV was mentioned. Also, does 18 Samsung strips on an 18 x 24 substrate count as fancy ?

I've watched that video now, forgive me about the delay.

What this guy states about UV being a necessary requirement to run P680 is simply wrong, and he didn't even mention a single reason of why that should be the case...? If he could answer that...

These statements around 2:00 are absurd, and can easily be disproven by what he stated later - that the water dissociation is a necessary requirement to gather electrons. Simply ask yourself - if that's true, then under artificial light, like lm301 etc - which doesn't contain UV at all - how come photosynthesis does still happen? PS w/o electrons???

Some of the stuff he explains is true, but very very basic, and I can hear out a lot of terminological inconcistencies, even beginner typos etc so I doubt he is a scientist...

He also doesn't seem to understand that p680 has it's absorption maximum at 680nm because these photons are actually still sufficient to raise an electron to a higher excitation state and then chemically conserve it (which happens at p680).

Actually the more closely a chlorophyl molecule is located at these binding sites the lesser energy they require, and the more distal they are away from it, the more energy is needed, as there is a "loss" when the exciton travels its path from either antenna or core to the centers p680 & p700. That's why PAR is PAR, and why IR/FR has to subtract phononic energy from the system to still be able to excitate p700 via far-red photons. And why there is this 'red drop'.... so I ask do we see somewhere a "UV drop" in absorption or PS rates when UV isn't present? No such thing is known, at least, not to me - the OPPOSITE is actually more true (check ICMag for pics) - we have a DROP in photosynthesis rates once one goes overboard with UVA/blue, and even slight UVB will cause a drop. These photons simply hold too much excess energy, and conflict with other stuff.

He may have confused the oxidising power of UV light with the reduction potential of p680, for the former you just have to know that the more energy a lightwave has, the more it has the power to generate radical oxygen species, which are bad and need to be dealt with chemically.

Landplants have acquired multiple other ways to make use of excitons, not all of them are used for photosynthesis, so there's a lot going on there and therefore I wouldn't rule out UV for some beneficial additional uses, but it's really not required at all for what he said.

Problem with these YT vids is they have had no review or critic from a full professor. It's much better IMO to read the standard academic teaching books.

Hope this helps you a bit out
 

drinkoldcoke

Active Member
True, like I said, not sure I can trust a guy that says "cartenoids" lol. What I gather so far (and my interest in UV) is secondary metabolites and enhancing the entourage effect'

Fortunately for me I just got my copy of "Plant Physiology And Development - Sixth Edition" compiled by Lincoln Taiz. Getting a bit old and outdated, but I plan on getting next years 7th edition.
 

oldbeancounter2

New Member

@2com

They were 99 at hlg I think. I wonder if the board only will be back.. Looks like the new solution is with a built in driver. I also think it may have a glass cover, being waterproof. Apparently only special glass for UV. @oldbeancounter is there glass covering the UV diodes?
Hey, lost my other account.
How did your smoke turn out unsing throse UV LED's?

Mine was so strong I stopped posting so I lost my account access I guess?


 
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