Modern leds and distance to plants

JohnFonda

JohnFonda

Tegrity Greenthumb
So I wanted to compile so info from different growers here. Pretty much what leds are you running at what stages. How high, how dimmed, what color etc. Switching from different boards has given me a bit of trouble and being able to run the lowest watts at the seedling early veg stage can be helpful.
 
JohnFonda

JohnFonda

Tegrity Greenthumb
What I've found. 2 324 quantum boards 3500k .~60 watts each. Start at 20 and lower to 18 within a few days. Seems to be a solid height for seedlings and early veg. Started at 24 too much stretch, went as low as 16 with signs of burning. 18 seems to be the sweet number in many cases. In flower full power I need the 324s at least 20 inches away from the canopy. The 132s 300k at 65 watts can get down to 12 inches without I'll effects imo.
 
X

Xs121

Member
Know your light PAR per Distance.

It's recommended to have an average of 65umol per sq ft or 700umol per sq meter. This is the considered 'optimal' PAR for grow light. Based on this info, you can determine the 'ideal' height from canopy of your particular light (bear in mind that this would also have an impact on light area coverage).

Once you have your ideal height, you can play with adjustment depending on what stage the plant is. If the plant is still trying to develop roots as in seedlings or clones, you might want to raise or dim the light. Bring it back to ideal height when the plant is growing as in veg. During flowering you might want to lower the light to increase light intensity for bigger yield( specially when supplementing with CO2).

In practice, I use QB with Meanwell HLG240 driver in a 2x4 space. Through my experience, my ideal height is just a little over 3 ft above the tray. Since I'm running perpetual SOG, this height covers any of my plants that are done stretching and plants that were just flipped and the occasional 12-12 seedlings. Sometimes, there are plant/s that may stretch more than I wanted and get closer to the light, I just supercrop the branch.
 
inthetrees

inthetrees

Active Member
I found that I had to re-program my brain as I was used to using air-cooled hps. The 'ol "lower till they show signs and then back off a bit" didn't work well with my LED panels. My 650's are mint at 18-20". IMO anything lower and its best to have a quantum meter so you can dial in the rest of the environment. Without one its a guessing game. I only recently heard about DLI and that explains why I had issues any lower.
 
Streetpro09

Streetpro09

Tester
inthetrees said:
I found that I had to re-program my brain as I was used to using air-cooled hps. The 'ol "lower till they show signs and then back off a bit" didn't work well with my LED panels. My 650's are mint at 18-20". IMO anything lower and its best to have a quantum meter so you can dial in the rest of the environment. Without one its a guessing game. I only recently heard about DLI and that explains why I had issues any lower.
Click to expand...
What is DLI?
 
inthetrees

inthetrees

Active Member
This is taken from @Wolverinegrown on IG...


"1605280593947.png


"I want to try and help as many people as I can with this information at once.

Because I get asked about canopy ppfd, light cycle times, & C02 levels a few times a day in my dms and try my best to explain to everyone, but have been slammed this month.

So above are some graphs to help you understand DLI numbers to aim for with cannabis plants at every stage of life. As well as the suggested C02 levels for those light intensities in correlation to photosynthetic production potential.

I run a 17hr on and 7hr off in veg with an 11hr on and 13hr off in flower using the dimmers to adjust intensities throughout the weeks. So not only saving money on electricity but the plants look happier, no longer stressed and overworked 💯" - @Wolverinegrown
 
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inthetrees

inthetrees

Active Member
After dumping cash on another LED panel I'm too broke to buy a quantum meter. For time being I'm just using a LUX app and referring to the conversion charts on Apogee's website to guesstimate where I'm at for intensity. I know that it's far from accurate given LED output but its the best i can do with what I got...

I was surprised how low his co2 levels were in veg... In the past I've read/been told that high co2 levels in veg are a must but I'm assuming that's just broscience. In the comments on this IG post theres a few guys that say they adjust their co2 to to match with EC. Since I'm in UC those digits are a no-go for me in late flower however I could see it applying to coco or soil. They do add up for me in veg though..

Regardless of not having a proper quantum meter, I've got my lights dialed down to 50% at about 30" and my co2 down to 450 and the plants are reacting far better in the last 2 days then they were prior. I'm also saving on my power and my heat is even lower now. Still running 18/6 for now...
 
Streetpro09

Streetpro09

Tester
inthetrees said:
After dumping cash on another LED panel I'm too broke to buy a quantum meter. For time being I'm just using a LUX app and referring to the conversion charts on Apogee's website to guesstimate where I'm at for intensity. I know that it's far from accurate given LED output but its the best i can do with what I got...

I was surprised how low his co2 levels were in veg... In the past I've read/been told that high co2 levels in veg are a must but I'm assuming that's just broscience. In the comments on this IG post theres a few guys that say they adjust their co2 to to match with EC. Since I'm in UC those digits are a no-go for me in late flower however I could see it applying to coco or soil. They do add up for me in veg though..

Regardless of not having a proper quantum meter, I've got my lights dialed down to 50% at about 30" and my co2 down to 450 and the plants are reacting far better in the last 2 days then they were prior. I'm also saving on my power and my heat is even lower now. Still running 18/6 for now...
Click to expand...

What meter are you looking at getting? If you don't mind sharing.
 
NoWaistedSpace

NoWaistedSpace

I'm Hoarding Skunk
inthetrees said:
This is taken from @Wolverinegrown on IG...


"View attachment 77744


"I want to try and help as many people as I can with this information at once.

Because I get asked about canopy ppfd, light cycle times, & C02 levels a few times a day in my dms and try my best to explain to everyone, but have been slammed this month.

So above are some graphs to help you understand DLI numbers to aim for with cannabis plants at every stage of life. As well as the suggested C02 levels for those light intensities in correlation to photosynthetic production potential.

I run a 17hr on and 7hr off in veg with an 11hr on and 13hr off in flower using the dimmers to adjust intensities throughout the weeks. So not only saving money on electricity but the plants look happier, no longer stressed and overworked 💯" - @Wolverinegrown
Click to expand...
Nice chart. Thanks for the info. I have no less than 800 CO2 levels at all times. I related it to fully organic grows keeping the CO2 levels that high.
 
inthetrees

inthetrees

Active Member
Streetpro09 said:
What meter are you looking at getting? If you don't mind sharing.
Click to expand...
The Apogee MQ-500 looks like the best option but its $800+ CAD. Sun Systems seems to have a decent unit for about $300 cheaper, but I'd rather invest a little more in the Apogee. The Hydrofarm unit is half the cost but has some horrible reviews. If you find another option please let me know lol!
 
inthetrees

inthetrees

Active Member
Hotwired said:
I am buying an HLG Scorpion Rspec the beginning of next year. I have loved my 550 Bpsecs in veg. I'm ready to try LED out in flower now.
Click to expand...
Thats awesome man those things look deadly! When I first looked at the HLG Canada website they wanted like $1500+ CAD for the 600's... I had a budget so I dumped $2k into my Meijiu's instead and then another 1k on this Hortibloom. Few days later I see the Scorpions and go back to the HLG website... Now the 600's are $1188 lol. I'll be switching over to the HLG's by summer. Had enough dickin around from these Chinese lights. Love the light compared to my HPS but just a guessing game what your truly getting for diodes.
 
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