LED spectrum

TwoWongsDontMakeAWhite

Well-Known Member
Has anyone run any tests comparing white light LED to the LEDs like sanlight that have a spectrum that looks very warm white with lots of extra red very similar to HPS spectrum

Would a 280w expensive sanlight give any advantage over a cheaper white 400w vipaspectra white light for flowering?

I have read that blue/cold/white light is more efficient to produce than warm/red light
But red/warm light is more effective to the plant the plant can make use of red/warm white light via a less complex process so taking this all into consideration does it balance itself out?

White/blue is more efficient with power usage
But red is more effective at photosynthesis

I have not long switched over to LED I've gone with the cheaper white options first but plain to try a sanlight myself to see if the spectrum makes much difference?

I like the panel style LED (Samsung boards) vipaspectra etc with very little heat I can get them 6 to 9 inch from the canopy with very even spread of colas but the light is very white I am happy but I can't help but think it should be that 3000k kind of colour
Do you guys think this is overstated and power matters more than spectrum?
 

grotbags

Well-Known Member
Has anyone run any tests comparing white light LED to the LEDs like sanlight that have a spectrum that looks very warm white with lots of extra red very similar to HPS spectrum

Would a 280w expensive sanlight give any advantage over a cheaper white 400w vipaspectra white light for flowering?

I have read that blue/cold/white light is more efficient to produce than warm/red light
But red/warm light is more effective to the plant the plant can make use of red/warm white light via a less complex process so taking this all into consideration does it balance itself out?

White/blue is more efficient with power usage
But red is more effective at photosynthesis

I have not long switched over to LED I've gone with the cheaper white options first but plain to try a sanlight myself to see if the spectrum makes much difference?

I like the panel style LED (Samsung boards) vipaspectra etc with very little heat I can get them 6 to 9 inch from the canopy with very even spread of colas but the light is very white I am happy but I can't help but think it should be that 3000k kind of colour
Do you guys think this is overstated and power matters more than spectrum?
any pics of the sanlight spectrum?, last sanlight specs i seen were unextraordinary...

with white diodes the higher the kelvin (white/blue) the more efficient they are, thats because they are based on a blue die, they then coat with different phosphors to make them warmer/yellower (lower the kelvin) the more yellow orange you go the thicker (not quite right really but it will do) the phosphor the lower the efficiency.

thats why so many lights are 4000k whites or 50/50 5000k,3000k mix with added 660's.

i think standard sodiums are around 1700k.

i think spectrum matters more than outright efficiency, ie id rather have a nice full high cri spectrum with a bit of uv ect at 2.5 umol/j than the standard 80cri 4000k white + 660's at 2.9 umol/j...
 

1212ham

Well-Known Member
any pics of the sanlight spectrum?, last sanlight specs i seen were unextraordinary...

with white diodes the higher the kelvin (white/blue) the more efficient they are, thats because they are based on a blue die, they then coat with different phosphors to make them warmer/yellower (lower the kelvin) the more yellow orange you go the thicker (not quite right really but it will do) the phosphor the lower the efficiency.

thats why so many lights are 4000k whites or 50/50 5000k,3000k mix with added 660's.

i think standard sodiums are around 1700k.

i think spectrum matters more than outright efficiency, ie id rather have a nice full high cri spectrum with a bit of uv ect at 2.5 umol/j than the standard 80cri 4000k white + 660's at 2.9 umol/j...
Here's a Sanlight spectrum.
1623365635478.png
 

MidnightSun72

Well-Known Member
@salmonetin posted a nice link from Valoya with a video talking about white and "pink" (white and purple/red) spectrum lights.

but also weighting that with the fact that Bruce Bugbee research shows regardless of spectrum and light used as long as the plants receive the same amount of PAR they will yield exactly the same.

we do know that spectrum influences the shape of the plants though. So you can use to achieve certain qualities, like more or less stretch.
 

Rocket Soul

Well-Known Member
@salmonetin posted a nice link from Valoya with a video talking about white and "pink" (white and purple/red) spectrum lights.

but also weighting that with the fact that Bruce Bugbee research shows regardless of spectrum and light used as long as the plants receive the same amount of PAR they will yield exactly the same.

we do know that spectrum influences the shape of the plants though. So you can use to achieve certain qualities, like more or less stretch.
Thing is spectrum can also speed up or slowdown development: if you're giving the same par but one flower cycle turns out 10 weeks and another 7 then theres a difference in yield.
 

Star Dog

Well-Known Member
I'm using two lights one is a mix of uv 3k and 5k (Tsl2000) it's visibly warmer than the other light a 4k +uv.

One plant gets both lights and there's no notable difference between growth, the other only gets the tsl there's no obvious difference in growth at 4 wks 12-12.

It's my 1st led grow so that's the limit of my experience with different colours.
 

MidnightSun72

Well-Known Member
Thing is spectrum can also speed up or slowdown development: if you're giving the same par but one flower cycle turns out 10 weeks and another 7 then theres a difference in yield.
Totally agree. But I think that gets complicated as well because in my experience plants that finish early don't yield as much as those that go a couple weeks longers. So I wonder if you avg'd your yield/week spent or per kwhr how different a 7 week finish would be vs a 10 week finish.

also can you really make a plant finish 3 weeks later or earlier with just spectrum? Very curious about this.
 

TwoWongsDontMakeAWhite

Well-Known Member
@salmonetin posted a nice link from Valoya with a video talking about white and "pink" (white and purple/red) spectrum lights.

but also weighting that with the fact that Bruce Bugbee research shows regardless of spectrum and light used as long as the plants receive the same amount of PAR they will yield exactly the same.

we do know that spectrum influences the shape of the plants though. So you can use to achieve certain qualities, like more or less stretch.
That is very interesting so taking this in consideration it would be wrong for me to assume a sanlight would
be better than the p4000 for yield but might have an influence on shape but if they were the same wattage?
the p4000 which was much cheaper almost half the price than a sanlight but its 120 watts more power
the sanlight has supposedly the better flowering spectrum i mention sanlight only because
the spectrum is different from most of the other lights that are more blue and sanlight is similar looking to HPS which i am much more familiar with
people who say the p4000 should only ever be used as a veg light do you think that is not accurate?
one thing i have noticed straight away with LED over HPS is the stretch during flower is much less i am growing
my plants longer under the p4000 because they will stretch much less than HPS
overall i am happy with the results and wouldn't consider switching back to HPS that would be ridiculous
i was trying to put a number on it or a percentage like an average overly blue spectrum 4000k to 5000k vipaspectra p4000
is 10% less effective than the best tuned spectrum so that i can add up if i think the extra cost is worth it
 

Alctrz8849

Well-Known Member
Any idea the price on their lights
That is very interesting so taking this in consideration it would be wrong for me to assume a sanlight would
be better than the p4000 for yield but might have an influence on shape but if they were the same wattage?
the p4000 which was much cheaper almost half the price than a sanlight but its 120 watts more power
the sanlight has supposedly the better flowering spectrum i mention sanlight only because
the spectrum is different from most of the other lights that are more blue and sanlight is similar looking to HPS which i am much more familiar with
people who say the p4000 should only ever be used as a veg light do you think that is not accurate?
one thing i have noticed straight away with LED over HPS is the stretch during flower is much less i am growing
my plants longer under the p4000 because they will stretch much less than HPS
overall i am happy with the results and wouldn't consider switching back to HPS that would be ridiculous
i was trying to put a number on it or a percentage like an average overly blue spectrum 4000k to 5000k vipaspectra p4000
is 10% less effective than the best tuned spectrum so that i can add up if i think the extra cost is worth it
Wattage is a terrible way to gauge what you need for plants. Wattage is a direct relation of power needed to create light, it is not a measure of what a plant uses. It's widely used because that was the most common info available and only what was needed at the time. Now with everything legal, use PAR, PPFD, PPF and spectrum to determine plant needs. Fluence is one of the BIG MFRs who involve themselves in study cases and offer up some great info on their website!

 

TwoWongsDontMakeAWhite

Well-Known Member
Any idea the price on their lights

Wattage is a terrible way to gauge what you need for plants. Wattage is a direct relation of power needed to create light, it is not a measure of what a plant uses. It's widely used because that was the most common info available and only what was needed at the time. Now with everything legal, use PAR, PPFD, PPF and spectrum to determine plant needs. Fluence is one of the BIG MFRs who involve themselves in study cases and offer up some great info on their website!

wattage is all part of the equation i am attempting to get a clear answer
with all things considered i was initially comparing the sanlight and the p4000 they are 120 watts appart
some would say that is not a fair comparison
i think i already have enough of an answer i don't think ill bother buying a sanlight just yet ill see what the p4000 can do with a few
different plants i was thinking maybe i was being a bit cheap and my plants were missing something because of all that blue and not much red
i like the idea of a light that red blue and green can be controlled but if that only really controls shape
rather than yield i am not going to spend extra money to control shape
 

grotbags

Well-Known Member
That is very interesting so taking this in consideration it would be wrong for me to assume a sanlight would
be better than the p4000 for yield but might have an influence on shape but if they were the same wattage?
the p4000 which was much cheaper almost half the price than a sanlight but its 120 watts more power
the sanlight has supposedly the better flowering spectrum i mention sanlight only because
the spectrum is different from most of the other lights that are more blue and sanlight is similar looking to HPS which i am much more familiar with
people who say the p4000 should only ever be used as a veg light do you think that is not accurate?
one thing i have noticed straight away with LED over HPS is the stretch during flower is much less i am growing
my plants longer under the p4000 because they will stretch much less than HPS
overall i am happy with the results and wouldn't consider switching back to HPS that would be ridiculous
i was trying to put a number on it or a percentage like an average overly blue spectrum 4000k to 5000k vipaspectra p4000
is 10% less effective than the best tuned spectrum so that i can add up if i think the extra cost is worth it
there is nothing special about that sanlight spectrum, looks pretty standard 4000k plus a load of 660's and a sprinkle of 730's, and at 2.7 umol/j its not that great for 2021.
plus i dont like the whole small footprint design, you want to spread that light about.
 

Alctrz8849

Well-Known Member
wattage is all part of the equation i am attempting to get a clear answer
with all things considered i was initially comparing the sanlight and the p4000 they are 120 watts appart
some would say that is not a fair comparison
i think i already have enough of an answer i don't think ill bother buying a sanlight just yet ill see what the p4000 can do with a few
different plants i was thinking maybe i was being a bit cheap and my plants were missing something because of all that blue and not much red
i like the idea of a light that red blue and green can be controlled but if that only really controls shape
rather than yield i am not going to spend extra money to control shape
Yeah Fluence covers the far left UV blue and far right deep red in their link I previously posted in a case study. Interesting stuff!!
 

TwoWongsDontMakeAWhite

Well-Known Member
see i thought you might have all said don't use that p4000 it's terrible its only for veg!
i have put the sanlight on a pedestal that it does not deserve lol
i feel less of a cheapskate now :D
i'm running the p4000 in just a 4x2 so its getting lots of light anyway albeit very blue it doesnt look
as "cool" as a MetalH and iv'e grown some lovely buds with just a MH many years ago
 
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