ComputerSaysNo
Well-Known Member
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.
How much light do you really need?
- Thread starter Bignutes
- Start date
-
- Tags
- light sizing square foot watts
I also believe that clones just need "whatever light", they don't have to be under CFL or under especially low light.
VincenzioVonHook
Well-Known Member
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..
Bignutes
Well-Known Member
Yeah my veg light is set to 24 w/sqft but mind you it’s for 15 hours
ComputerSaysNo
Well-Known Member
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.
Star Dog
Well-Known Member
What kind of light meter do you use?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%give or take.
Coldnasty
Well-Known Member
Still rolling out with the old hps myself
Coldnasty
Well-Known Member
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 lolFalse, 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.
View attachment 5071797
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
calvin.m16
Well-Known Member
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.
calvin.m16
Well-Known Member
Bignutes
Well-Known Member
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?
calvin.m16
Well-Known Member
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.
Bignutes
Well-Known Member
That’s exactly I how do it and about the only way for the average grower.
calvin.m16
Well-Known Member
Yessir and unless you're willing to spend $500 or more on a light instrument there is no point in even wasting your time.
Markshomegrown
Well-Known Member
ComputerSaysNo
Well-Known Member
Yes, it is a little arbitrary, but that does not make it useless. It just makes it "not perfect".
I can live with that.
VincenzioVonHook
Well-Known Member
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.
ComputerSaysNo
Well-Known Member
Here is an instruction video that also gives some calibration values for commonly used lights:
Markshomegrown
Well-Known Member
I brought the dr meter lux meter because you can time the lux by .015 and get the par level, (good enough IMO)
migro did a similar video.
migro did a similar video.
Bignutes
Well-Known Member
For modern LEDs I think the same can be said for W/sqft. It’ll get us in the ballpark
ComputerSaysNo
Well-Known Member
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.