Yeah checked it out. Seems it was around the 800 mark. Nice yield.@Abiqua @Trippyness because it applies so well to what we are talking about here, ill link to the spot in the video where i report the results. its a blue dream dominant strain in 5g canna coco pots.
@churchhaze it looks like I was indeed using more like 750-790 umols of photons per second per square meter.
8:03 mark (wont let me link to that exact spot)
4800 PPFD is pretty intense. I'm not sure anything could survive in that environment. Do you have a citation for it?Note that some commercial growers are using upwards of 4800 PPFD because their fixed assets and personnel costs are more expensive than additional watts.
Thats way too much light, will burn and kill plants no doubt. Sounds like speculation.4800 PPFD is pretty intense. I'm not sure anything could survive in that environment. Do you have a citation for it?
I have been chatting with gavita a little about par readings...
"Dear ****,
The ppfd you will read under a lamp depends on the reflector, so it is impossible to compare based on a ppfd measurement at a distance. I have not seen any LED fixtures yet that have a better spectrum and are more efficient than Pro-line HPS, not even at the same power. As said, ppfd at a distance doesn't say anything.
The recommended height from the crop for the pro-1000 is about 80-90 cm, depending is you overlap or not. 2000 umol s-1 m-2 is 30% above the saturation level. We recommend 1000 umol m-2 s-1.
The only thing you can do is measure in a dark room om a given footprint, do a matrix measurement (at least about 40 measurements) and average them over the lit surface.
It would be handy if manufacturers just publish their ppf. We measured Hortilux at a bit lower than 1800 umol s-1 @ 1000W lamp power."
Pretty much goes right with my umol theory.
They are a nice company, and for hps are the best for sure...but honestly they can't think their spectrum is better than led's.
Gavita was quick this time...
The DLI, optimal PPFD and saturation level depends greatly on the crop. I have no public papers to share about this, these are copyrighted research papers we can not distribute. But for a medical cannabis crop you will have a linear increase in yield following the ppfd to about 1000-1100 umol. After that the curve starts to top off with a saturation of the plant between 1400 and 1600 umol m-2 s-1. Beyond that yield decreases.
The standard red an blue narrowband LEDs certainly do not have a better spectrum than HPS. Though HPS lacks blue and green it does have a much wider spectrum of light than the average monochromatic LED, or even 3 at different wavelengths. We have yet to see a fixture (not a lab theoretical maximum output) that is able to beat HPS.
There are plants that thrive under orange and red light. In any case you should ideally not hang only HPS in a climate room. Professional climate rooms use a mixture of HPS and MH or just MH.
The Pro 1000 needs about 80-90 cm distance for an average of 1000 umol m-2 s-1.
Gavita and I differ greatly in ideal spectral performance for sure, obviously they are not up on their white led tech...but there umol levels are right inline with mine so think that I am on the right path for the ultimate light.
GG, I usuially agree with you but saying 600 is shit is really stubborn. Yes your right on the g/sf.Let's get something straight...g/w means nothing. (grams/sqft) and (grams/KwH) are the only real metrics to use for comparison.
I refer you to post #416 from me in here for PPFD to yield differences...with pictures...
https://www.rollitup.org/t/have-any-of-you-diy-cob-growers-finished-a-crop-under-1000w-de-hps-poll.883181/page-21#post-12354605
Increase in PPFD is clearly shown in results and seen personally/subjectively. 700-1000µmols has also been shown, talked about, and recommended by others for years. all based on real world and lab studies.
500ppfd, 600ppfd is weak as hell. Of course you are getting good g/w...but g/sqft is what matters.
Look at the standards of growing. hps= 600w for 3x3, 1000w for 4x4...even 400w in 2x2's. That is looking at an average above 1000µmols PPFD for either. That's what the guys getting 2lb+ consistently from a 4x4+space. That is the goal that leds need to live up to. Not some misrepresenting g/w. Professional growers have been growing with 800µmols+...that"+" is key, cause most are over 800.
That is all real world results. Backing what theory says should be the case.
I have added PPFD to my spreadsheet...G/sqft and G/KwH are on there too. As well as your basic g/w.
View attachment 3666768
Obviously genetics and veg time are a factor, but in the same conditions how much yield increase from 600 to 800 is all im asking. I love that you attatch real world data. Really helps the communityGG, I usuially agree with you but saying 600 is shit is really stubborn. Yes your right on the g/sf.
I did see your post but nothing conclusive. Your attatchment is blury as well. I have no doubts 800+ppfd increases yield compared to 600 but by how much per sqf?
Thanks for the input.
Descent. I pull 3.5oz a sq/f with Blue Dream using Blurple. Plan on upgrading.I pulled 1.58 ounces per square foot with 940 PPDF, unproven pheno's and a quite uneven canopy my first time with the Cree 3590 COB's...
its an impossible question. doh.Obviously genetics and veg time are a factor, but in the same conditions how much yield increase from 600 to 800 is all im asking. I love that you attatch real world data. Really helps the community
General guideline. Mainly to see how much difference. Seems i may have to test it in a small run.its an impossible question. doh.
Obviously genetics and veg time are a factor, but in the same conditions how much yield increase from 600 to 800 is all im asking. I love that you attatch real world data. Really helps the community
I'm sure I can and will do better down the road. I was pheno hunting not looking to yield. I think when I'm running full speed I'm still not going to touch 3.5 a sq/f...Descent. I pull 3.5oz a sq/f with Blue Dream using Blurple. Plan on upgrading.
With a better yielder you could surely double your yield.