How much light do you really need?

VincenzioVonHook said:
I don't believe in nursing seedlings anyway. They just go under a 120w QB at full pelt and never had issues. Sometimes I swear the less effort I put in, the better.
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Bugbee mentioned that same thing (paraphrasing: "even small plants can take a lot of light").
I also believe that clones just need "whatever light", they don't have to be under CFL or under especially low light.
 
ComputerSaysNo said:
Bugbee mentioned that same thing (paraphrasing: "even small plants can take a lot of light").
I also believe that clones just need "whatever light", they don't have to be under CFL or under especially low light.
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Yep, I've had seedlings under 60 DLI no problems in the same tent as flowering autos in mid summer. These plants are more hardy than people give them credit for..
 
ComputerSaysNo said:
Bugbee mentioned that same thing (paraphrasing: "even small plants can take a lot of light").
I also believe that clones just need "whatever light", they don't have to be under CFL or under especially low light.
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Yeah my veg light is set to 24 w/sqft but mind you it’s for 15 hours
 
Bignutes said:
Yeah my veg light is set to 24 w/sqft but mind you it’s for 15 hours
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Which brings up another point: not only is Watts/area not very informative, what actually counts is the DLI (usable light summed up over time). The DLI puts everything into one number: photons that actually reach the plant over time.

With regards to economy, the only useful measure is weight-per-kWh (e.g. 1g/kWh), but of course nobody ever uses that. Apparently "I got about a pound from my 400W light" has more appeal to people, but it is ultimately meaningless.
 
Markshomegrown said:
Just lifted the end led reflector on the bar of LEDs(6 in a row between the led panel and HPS), at 12" it read 35k(lux) and with the reflector, it went up to 41k(lux) so it does make it a lot more effective, that's about 17% :weed: give or take.
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What kind of light meter do you use?
 
calvin.m16 said:
False, the Gavita CT 1930e LED is a direct replacement for 1000w HPS. IDGAF what any of you LED fanboys say your not competing with a 1000w DE HPS with your 680 watt LEDs.

Unless you're running 100 fixtures you're not even saving enough money to make it worth the loss in yield and quality.

Gavita CT 1930e is $1,200-1,300 per/unit. I'll stick to my 1000w Double Enders. LUXX DE HPS fixture bulb and power cord $230 before tax.
www.luxxlighting.com

LUXX DE 1000W HPS 240v

DescriptionLuxx DE 1000w HPS 240vThe Luxx Lighting 1000w DE HPS fixture is the result of thousands of harvests, decades of cultivation experience, and passion for the garden. Every component of the DE 1000w was purpose-designed and built from the slim-line reflector to the low profile ballast...
www.luxxlighting.com www.luxxlighting.com
View attachment 5071797
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Lmao @ the “jungle boys run this light” at the end. Not taking anything away from them or the light, it’s just funny how their marketing game is so strong that even the light company riding those coat tails. Legit it made me lol
 
Coldnasty said:
Lmao @ the “jungle boys run this light” at the end. Not taking anything away from them or the light, it’s just funny how their marketing game is so strong that even the light company riding those coat tails. Legit it made me lol
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Yeah the Jungle Boys do run those lights though. GrowGreenMI doesn't need to hype products though they are one of the largest grow stores in Michigan. Their store is literally 75,000 square feet. Jungle Boys run all of LUXX products though so it's no news to anyone.

They're really good people I order online and go in their store.
GrowGreen MI has been serving Michigan and the lower 48 since 2009 with over 350,000 customers.
GrowGreen MI has a fleet of trucks to deliver pallets of soil right to your door in Michigan and Pallet shipping to our out of state friends.
GrowGreen MI is located in a 75,000 square foot facility on 5 acres with eight truck docks in Whitmore Lake, MI.
GrowGreen MI offers customers the ability to walk in and purchase, or we can ship the items to 48 states.
Grow Green has a fleet of vehicles to discretely deliver customer products.
Grow Green buys products from suppliers in BULK and that savings is passed onto you: the GROWER.
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ComputerSaysNo said:
Which brings up another point: not only is Watts/area not very informative, what actually counts is the DLI (usable light summed up over time). The DLI puts everything into one number: photons that actually reach the plant over time.

With regards to economy, the only useful measure is weight-per-kWh (e.g. 1g/kWh), but of course nobody ever uses that. Apparently "I got about a pound from my 400W light" has more appeal to people, but it is ultimately meaningless.
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DLI is kind of a useless metric too. DLI measures PAR from 400–700 but it could be all in one range of 400-500 nm. Then what about less than 400 and more than 700?
 
Bignutes said:
DLI is kind of a useless metric too. DLI measures PAR from 400–700 but it could be all in one range of 400-500 nm. Then what about less than 400 and more than 700?
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If you're not using at least a Apogee MQ-500 Full-Spectrum Quantum Meter or better save your money and crank them lights up or down based on looking at the plants, if they are showing light stress turn them down or raise lights if they're taking the light crank it up or lower it closer to the plants.
 
calvin.m16 said:
If you're not using at least a Apogee MQ-500 Full-Spectrum Quantum Meter or better save your money and crank them lights up or down based on looking at the plants, if they are showing light stress turn them down or raise lights if they're taking the light crank it up or lower it closer to the plants.
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That’s exactly I how do it and about the only way for the average grower.
 
calvin.m16 said:
Yessir and unless you're willing to spend $500 or more on a light instrument there is no point in even wasting your time.
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You know the apps that use external BT sensors have a calibration setting? For example I rent an apogee from the hydro store, set the closest spectrum in the app and use the calibration setting to make sure you are reading within a coupe of percent the same as the apogee.

It's really handy tbh to get a good estimate of your intensity. Last time it was off by 11%, and once you calibrate is it's within throwing distance.

People say to just calibrate by using PAR maps from the manufacturer, but I'd rather hire a decent quantum sensor to calibrate.

I would just buy a quantum sensor and a spectrometer if I wasn't ghetto AF.

St the end of the day tho, as you said, you can just look at the plant. But I'm just interested in lighting in general so I measure for shits and giggles.
 
VincenzioVonHook said:
You know the apps that use external BT sensors have a calibration setting? For example I rent an apogee from the hydro store, set the closest spectrum in the app and use the calibration setting to make sure you are reading within a coupe of percent the same as the apogee.
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Here is an instruction video that also gives some calibration values for commonly used lights:

 
Bignutes said:
For modern LEDs I think the same can be said for W/sqft. It’ll get us in the ballpark
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Watts/area says nothing about the hanging height or the actual time the light is turned on.

I can hang a 2000W light 2 meters above a 0.25 m² grow space and run it for a random amount of time per day. The numbers are meaningless now.

If somebody tells you X Watt per ft², you need to make a lot of assumptions to draw any conclusions from that.

DLI actually gives you an amount of light that reached the plant. The number is so much more informative.
 
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