Yodaweed
Well-Known Member
So what you are saying is his cutting edge research department (some guy on a forum) is wrong? How could this be......he even stated it was proven in a very scientific study...
Most efficient chip
- Thread starter awil7698
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MeGaKiLlErMaN
Well-Known Member
Want to play overwatch? CRI is in a run all by itself currently ans we will see if there are yield differences soon enough.
And the troll shows up as always
Yodaweed
Well-Known Member
If you like high cri get a plasma light they are the highest available.
MeGaKiLlErMaN
Well-Known Member
True but there's also 97Cri ones as well which would still be better.
Stephenj37826
Well-Known Member
NapalmD
Well-Known Member
They definitely finish up a little earlier. I'll be able to gauge it better in about 10 days.
Running 2 cuts now under 90cri that I cut the lights on at day 63 under 80cri. Looking to cut the lights in 10 days on day 57. Once they dry I'll be able to tell the difference,if any, in smell, potency and density.
But from previous experience it shaved 5 days off finish time.
PicklesRus
Well-Known Member
So you're saying that higher CRI finishes faster, not longer?
NapalmD
Well-Known Member
Yes, faster.
Any chance you remember where this thread is at? The only reason I could see this being true is if red shortens flower duration compared to amber since 3000k 80 cri peaks at ~605nm while the 90 peaks at 630nm.
verticalgrow
Well-Known Member
Stephenj37826
Well-Known Member
I think it has more to do with either the ratio of red to far red or the additional far red. Far red helps with florigen production. The flowering hormone. So to me yield has as much to do with time as it does with quantity. If you shave off 8+ days vs 4000k 70 CRI which I have heard of then you have gained quite a bit of ground imho.
wietefras
Well-Known Member
@Stephenj37826 IF you shave of 8+ days then perhaps yes, but in reality anecdotal evidence indicates it's more like 3-5 days at best. And then only based on mostly vague claims like "on previous experience" or "other factors might have had an influence as well". So it might not have any meaningful impact at all. When Citizen's own PAR measurements show that their 90 CRI COBs produce 9% less PAR light than the 80 CRI ones, is that really worth it?
I wonder what Rahz's side-by-side test shows though. Should be more apparent if the difference is more than a few days if they are growing side by side.
I tried far red myself (albeit with FR leds) and the difference wasn't big enough to really say that it was the far red or just a normal fluctuation between grows. I had a bigger impact (ie significantly bigger than the margin of error) in flowering duration by adding more P to the nutrients.
Either way, I don't like FR during veg phase and especially not during the flowering switch. Really don't like the added stretch. So I'd rather go for FR leds anyway instead of wasting PAR light for more FR in the COBs. It's the whole reason why people go through the bother of switching out their HPS and MH bulbs during a grow.
Tests did show that tomatoes receiving extra FR light were sweeter than ones without. I would like to try that difference still. but that was with FR doses like in sunlight. So with 1:1: ratio's of red and far red or 2:1 at the least. COBs only emit tiny amounts of FR compared to red.
I wonder what Rahz's side-by-side test shows though. Should be more apparent if the difference is more than a few days if they are growing side by side.
I tried far red myself (albeit with FR leds) and the difference wasn't big enough to really say that it was the far red or just a normal fluctuation between grows. I had a bigger impact (ie significantly bigger than the margin of error) in flowering duration by adding more P to the nutrients.
Either way, I don't like FR during veg phase and especially not during the flowering switch. Really don't like the added stretch. So I'd rather go for FR leds anyway instead of wasting PAR light for more FR in the COBs. It's the whole reason why people go through the bother of switching out their HPS and MH bulbs during a grow.
Tests did show that tomatoes receiving extra FR light were sweeter than ones without. I would like to try that difference still. but that was with FR doses like in sunlight. So with 1:1: ratio's of red and far red or 2:1 at the least. COBs only emit tiny amounts of FR compared to red.
Stephenj37826
Well-Known Member
It's 3-5 days for 80 CRI vs 90 CRI. As the OP mentioned 70 CRI having the most ppf/w this is relevant. Also to consider is sure there is a 9% reduction in ppf (400-700) NM because most of that energy is falling in the 701+ range. Did that make it wasted? Hell no. I know there are alot of growers that see improvements due to the Emerson effect. It's all splitting hairs honestly and comes down to personal preference but to dismiss 90 CRI because some of it's energy doesnt fall in the 400-700 range is not doing it justice. Also to consider is everyone talks about UV(specifically UV-B) as very desirable during flowering. Well that doesn't fall in the 400-700 range either but it's effectiveness isn't in question at increasing terpene yield.
That being said everyone has his or her preference and there isn't a wrong answer. One thing I can note is most growers who have tried 3000k 90 prefer it vs 3000k 80 cri. Of course take that with a grain of salt I suppose.
PetFlora
Well-Known Member
~ 5 years ago- a life time in LED knowledge, a person who long since stopped posting added some great intel to my then thread. The highlight of which has to do with the extreme value of 630nms. So for whatever this is worth...
As one can see, the CREE Neutral White (I call it 'Goldilocks', because it's almost 'just right'
Couple that with strong white light (green-response chlorophyll extending throughout and deep into leaf structures, with a net effect at or near that of the (mostly) surface-level blue and reds), which also takes care of most of the ~660nm+ you actually need for photomorphogenesis - and you can get by with 630nm reds just fine.
(i.e. 630nm red is ~95% of the PSR of 660nm, AND they currently still have ~20-30% greater radiometric efficiency - as well as being cheaper than the deep reds - so there's more 'bang for the buck'):
Something like that would probably meet the needs of ~95% of today's growers.
Stephenj37826
Well-Known Member
~ 5 years ago- a life time in LED knowledge, a person who long since stopped posting added some great intel to my then thread. The highlight of which has to do with the extreme value of 630nms. So for whatever this is worth...
As one can see, the CREE Neutral White (I call it 'Goldilocks', because it's almost 'just right') has a RSPD that still allows nearly ~25% of its total power in the blue range (and plants only really 'need' ~8-10%), and more than 1/3 of which (i.e. the area under the curve) is over ~580nm or so (which has a Photosynthetic RS of over 90%!) - which is much better than even your typical 'Enhanced HPS'.
Couple that with strong white light (green-response chlorophyll extending throughout and deep into leaf structures, with a net effect at or near that of the (mostly) surface-level blue and reds), which also takes care of most of the ~660nm+ you actually need for photomorphogenesis - and you can get by with 630nm reds just fine.
(i.e. 630nm red is ~95% of the PSR of 660nm, AND they currently still have ~20-30% greater radiometric efficiency - as well as being cheaper than the deep reds - so there's more 'bang for the buck'):
Something like that would probably meet the needs of ~95% of today's growers.
And 90 CRI peaks at 630 NM
PicklesRus
Well-Known Member
Why doesn't someone setup a side by side by side by side test lab.
It seems crazy it isn't already done here - research companies are doing that for other crops.
It seems crazy it isn't already done here - research companies are doing that for other crops.
Olive Drab Green
Well-Known Member
Yeah, but PPFD goes up significantly. My 3500k 80CRI CXB3590s driven at 2150mA put out ~100 less PPFD than my 90 CRI 3500k Vero29C (Seventh Gen) driven at 1670mA.To answer the OP's question:
70CRI = 70%eff
80CRI = 65% eff
90CRI = 60% eff
is that correct