COB vs blurple spectra

sorry for the several spectra thread going, im gonna try to consolidate a few different threads here

first off: the infamous mccree curve were all familiar with



and a chlorophyll curve ill borrow from another thread:



@SupraSPL posted this most excellent curve of popular color temps in this thread . Im not sure how universal and hard and fast these are for different mfrs and their individual color temps.



Lastly we have this image of spectra i shot of two popular blurples who both claim to have a 'full spectra' of note is they are damn near identical except kind's blue range is slightly higher:



Presumably theyve put some research in (both companies claim to have plant scientists in the development team)

Point being note how much higher the 660 band is in this, where it seems to be on the lowe end of the color temp graph above.

for comparison, arguably one of the best HPS on the market right now, Ushio pro hilux gro DE, 2100K:



looking at the data above, i feel that really 3000K is pushing it too high for ideal flowering. like 2700 would be ideal. thoughts?

Based on your charts, it appears there's no reason to choose 2700, 3000, or 3500, when 4000 is near identical in red(looks like 5% less 660 red than 2700), and has more of everything else.

good observation!

yes but is more blue better?

i guess par light is par light

supra is an advocate for as little as possible. i could see where too much could make your crop leafy i guess.

maybe this is why lower color temps are less efficient. higher color temps have all of the same red plus more blue lacking in the lower color temps

also not sure how absolute that is. we need som real spectral data on these cobs

IIRC, the lower K lights have the blue dialed down rather than ramping up the red, so there's overall light loss when dropping to lower K.

I'd say more light is always better unless you're at the point where you're bleaching. I don't think more blue will make a strain more leafy, just tighter packed nodes.

I don't understand because you can vegg and flower with HPS but I don't see that you can do the same with any of the COB that are available right now or maybe I am wrong.

augusto1 said:

I don't understand because you can vegg and flower with HPS but I don't see that you can do the same with any of the COB that are available right now or maybe I am wrong.

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Defo wrong bro. I vegged with 3k cobs and much better veg then hps.

You can both veg and flower with Cobs.

Some plants do seem to appreciate a bit higher k rating. They just do. I am not committed to any single k rating. There will be more leafy development and less density(not much) with above 3000k or so. There may also be more of a complete expression of what your favorite plant is all about. That noted, more red tends to make bigger and denser.

The veros and Crees are putting out such a fuller spectrum. Closer to the sun and so much more efficient. The ushio is one of the better street light bulbs. Just a slight tweaking of not so good spectrum. Overwhelming sheer photon power makes up for that in hps at the expense of heat and light that the plant cannot use real well.

augusto1 said:

I don't understand because you can vegg and flower with HPS but I don't see that you can do the same with any of the COB that are available right now or maybe I am wrong.

Click to expand...

Veg 3k crees
Flower under the same crews


Sent from my iPhone using Tapatalk

Most hps charts do not show the huge IR spike! They all have it all but maybe plantmax is one of the only ones that was putting the whole chart on their box. Thanks for putting those charts up.

hillbill said:

Most hps charts do not show the huge IR spike! They all have it all but maybe plantmax is one of the only ones that was putting the whole chart on their box. Thanks for putting those charts up.

Click to expand...

Exactly as some companies are stuck in the old school thinking that plants don't use anything above 700nm. Which we know now isn't true it's just diminished vs the 400-700

hillbill said:

Most hps charts do not show the huge IR spike! They all have it all but maybe plantmax is one of the only ones that was putting the whole chart on their box. Thanks for putting those charts up.

Click to expand...

Far red is super important to plants but more for putting them to sleep like a baby. I've tried far red on all the time previously at my buddies grow and it seemed to stretch them out like mad compared to normal. Not a great test imo but we won't be doing it again. At least not at those levels. We now use it at lights off and my buddy gets almost a complete other run in during the year. Pretty awesome imo

Atulip said:

Based on your charts, it appears there's no reason to choose 2700, 3000, or 3500, when 4000 is near identical in red(looks like 5% less 660 red than 2700), and has more of everything else.

Click to expand...

The charts are showing relative intensity, so the levels aren't absolute/directly comparable between K temps.

Getgrowingson said:

Far red is super important to plants but more for putting them to sleep like a baby. I've tried far red on all the time previously at my buddies grow and it seemed to stretch them out like mad compared to normal. Not a great test imo but we won't be doing it again.

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It's not a great test, but it's so easy to come to a quick conclusion that most people refuse to ever do it again! This is why I dare people who don't believe in the effects of 730nm to turn it on during the day and see what happens. They will never question it ever again!!

Getgrowingson said:

Far red is super important to plants but more for putting them to sleep like a baby. I've tried far red on all the time previously at my buddies grow and it seemed to stretch them out like mad compared to normal. Not a great test imo but we won't be doing it again. At least not at those levels. We now use it at lights off and my buddy gets almost a complete other run in during the year. Pretty awesome imo

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and mother nature puts the plants into sleep all day long at this level of Far-Red...

guod said:

and mother nature puts the plants into sleep all day long at this level of Far-Red...

View attachment 3587974

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Brother Guod ,I wanted to ask something to you ...

Is there any evidence that higher green plants ( like mj ,for example ) do have Chlorophylls D & F (far red Chlorophylls ) ?
Or they are present only in marine plantae kingdom ,like red algae and cyanobacteria ?
Do you have any info / links ?

????



Relative spectral distribution chart with a peak higher than 100% ?
What kind of relative is that ?
Relative to what ?

kmog33 said:

Veg 3k crees
Flower under the same crews
Sent from my iPhone using Tapatalk

Click to expand...

what strain is that? looks fantastic curious if its a known stretcher

stardustsailor said:

Brother Guod ,I wanted to ask something to you ...

Is there any evidence that higher green plants ( like mj ,for example ) do have Chlorophylls D & F (far red Chlorophylls ) ?
Or they are present only in marine plantae kingdom ,like red algae and cyanobacteria ?
Do you have any info / links ?

Click to expand...

landplants have no Chlorophylls D or F (see MCCree) just only phytochrome as a sensor Pigment for Far-Red.

Chlorophyll a and b comes in different bindings on the molecular level which results in different absorption wavelengths.
but non of them are higher then 700nm

Photosystem I


Photosystem II


if you wont go deeper here are some Keywords for Google
CP43 (PsbC) and CP47 (PsbB)