MrTwist1
Well-Known Member
You are exactly right on both these points. Sometimes the aggressive attitude towards newcomers here pisses me off.
Is this a Vero 29 killer?
- Thread starter JorgeGonzales
- Start date
frica
Well-Known Member
Do you know what light schedule was used in the study?
A ppfd of 1500 over 18 hours is completely different than the same PPFD over 12 hours.
sixstring2112
Well-Known Member
average ppfd of this plant top to bottom side to side i would guess around 400. by the top colas reads around 800ppfd,and down by the soil its like 200 to 275 ppfd. those are all 35w cobs.im not saying 400 is the sweet spot,just that its very doable.
frica
Well-Known Member
Any way, there are diminishing returns as you go towards 1500PPFD.
600-900 is nicest if you want to maximize gram per watt, but marijunana is a high value crop so gram per watt isn't too important unless specific cases where you want to minimize wattage at all costs. Or the differences are really big.
Going higher than that it becomes increasingly beneficial to supplement with extra CO2.
But going from 1000 PPFD to 1500 will not have the same increase in yield as 600 to 1000 will do.
600-900 is nicest if you want to maximize gram per watt, but marijunana is a high value crop so gram per watt isn't too important unless specific cases where you want to minimize wattage at all costs. Or the differences are really big.
Going higher than that it becomes increasingly beneficial to supplement with extra CO2.
But going from 1000 PPFD to 1500 will not have the same increase in yield as 600 to 1000 will do.
DrMisunderstood
Member
I agree it is a small issue. The big issues are done. Now we have to work on the small stuff. The small stuff adds up.
Thermal dynamics are similar to electricity. When you have a lot of thermal flux moving along the same path the temperature increases..
Just like when current increases through a resistor the voltage increases.
To improve it, you either decrease the current or resistance. Or reduce the watts generated or increase the area for the thermal flux.
That means smaller light sources spread over a greater area.
I understand the logistics of doing that and the resistance in doing so. I think there is a DIY solution that will get the job done. I do not know it can be done, but I also do not know it cannot be done. I intend to find out.
Active cooling can only get so far with a CoB. I'd like to see 25°C junction temperatures. It may take an ice cube to do it with a discrete LED but it will probably take dry ice with a CoB.
DrMisunderstood
Member
I assume you got those numbers from a study like this:
Photosynthetic response of Cannabis sativa. to variations in photosynthetic photon flux densities, temperature and CO2 conditions
Suman Chandra, Hemant Lata, Ikhlas A. Khan, and Mahmoud A. Elsohly
National Center for Natural Product Research, School of Pharmacy, University of Mississippi, MS-38677, USA.
Department of Pharmacognosy, University of Mississippi, MS-38677, USA.
Department of Pharmaceutics, School of Pharmacy, University of Mississippi, University, MS 38677, USA.
Photosynthesis by temperature and PPFD
Mississippi moon, won't you keep on shinin' on me
Yeah, keep on shinin' your light
Gonna make everything, pretty mama
Gonna make everything all right
And I ain't got no worries
'Cause I ain't in no hurry at all
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DrMisunderstood
Member
http://www.academia.edu/6308454/Photosynthetic_response_of_Cannabis_sativa_L._to_variations_in_photosynthetic_photon_flux_densities_temperature_and_CO_2_conditions
They did not state a light schedule. In the studies I've seen the lights are on 24/7. If there is a schedule it's just another thing that can go wrong. For example if the lights did not turn on or off at any scheduled time, the experiment would have to be started over.
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nfhiggs
Well-Known Member
DrMisunderstood
Member
Diminishing returns would be something I would categorize as an obstacle.
I will not look at the world from a point of view of what cannot be done.
I do not believe in obstacles. They are imaginary. Life is much more interesting when you ignore the obstacles. Try it, ignore obstacles, it's fuckin' amazing.
DrMisunderstood
Member
Emphasis on SIMPLE!
nfhiggs
Well-Known Member
Simple as in a water block, pump, and large reservoir cooled using evaporation. Its highly effective.
DrMisunderstood
Member
This was my first prototype. I have since simplified it. Built it and learned.
The major issue this fixed was the single point of failure, one pump. Catastrophic failure if everything goes up in smoke.
I need to add an ice maker. Something like the top half of the machine below.
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SaltyNuts
Well-Known Member
I love where this thread is going. @sixstring2112 that DIY fixture is killing it and I always love the photos.
@DrMisunderstood check out this hardware and tell us what you think: https://chilledgrowlights.com/product-category/diy-led-grow-light-parts/diy-led-boards-and-heatsinks
@DrMisunderstood check out this hardware and tell us what you think: https://chilledgrowlights.com/product-category/diy-led-grow-light-parts/diy-led-boards-and-heatsinks
SaltyNuts
Well-Known Member
just need to park the water-cooled LED garden next to an ice-cold stream and get some drop through your square aluminum tubing on the way to the diy AC generater pulled from an old washing machine motor.
nfhiggs
Well-Known Member
No, you really don't. The amount of heat you will be pulling out of the lights is really not that much. Use evaporative cooling by simply running the outflow from the water blocks to a shallow tote, and increase the evap rate using a fan blowing across the surface. There is one guy here who has already done it this way and its quite effective. The water in his reservoir barely rises above ambient. room temp
DrMisunderstood
Member
Assholes!!!
Seeing this pissed me off: Real 1200 watt power draw – none of the silly marketing nonsense with “LED watts vs Electrical watts”
WTF is "Real watt power draw"? Like those other asshole that call watts true watts.
It appears they do parallel strings. You may get away with it with CoBs, but not strings of LEDs. They are going to have customer support issues up the ass, if people buy their shit.
You don't use lethal voltage and tell the customers to be careful. You have to make it impossible for the customer to kill themselves. Obviously no UL approval. Idiots.
Still smh after reading how LEDs work. Jesus fucking Christ.
Their site gives me anxiety. They're idiots. The product is okay but the people suck. No organization, stupid bullshit articles.
A $2,600 unit and if you want a longer cord you pay $5 extra for 5 feet more. Idiots. The one thing people know the value of and they over charge for it. That says "we charge too much for shit". Over $3,000 for a maxed out unit of Samsung 561 LEDs crammed into little boxes? I don't think so.
Selling at top tier prices with schlock tactics. Low lives sell LED fixtures by Wattage.
Anybody want to bet if they will be shipping on the "Release Date" June 19th?
They use the same photos for every unit?
Little boxes made of ticky-tacky,
Little boxes, all the same.
There's a green one and a pink one
And a blue one and a yellow one
They're all made out of ticky-tacky,
And they all look just the same.
Little boxes, all the same.
Yeah a green one and a pink one
And a blue one and a yellow one
And they're all made out of ticky-tacky
And they all look just the same.
Weeds was a great show. My kids were 12 and 14, we'd all sing Little Boxes together.
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SaltyNuts
Well-Known Member
Man you are one ornery old cuss. "Real watt power draw" is a euphemism used to distinguish from other LED grow-lights that advertise a "wattage" figure that is ostensibly derived from what they suppose to be the HID bulb equivalence, or whatever sounds good. So you get "800W" fixtures that actually consume 200W. The pop culture of LED grow lighting now recognizes this fallacy and so this is addressed by the term. I like the idea of the relatively high density of the board design and the independent white, blue, red, and UV channels. Do you think the design is any more dangerous to assemble compared to cobs or the quantum boards, or discrete-diode arrays?
