AFN welcomes Horticulture Lighting Group!

[LearningMore]

Here is a chart that will help telling you approximately how many lux a plant is happiest with. This can vary a little from plant to plant. With this knowledge and a decent quality Lux Meter you will have your lights dialed in all the time which greatly benefits your plants and your grow. Below the simple chart is a photo of the Lux meter I use. Price is $35-$40 depending where you buy it.

HOW MUCH LIGHT DO YOUR CANNABIS PLANTS REQUIRE?

• Clones and seedlings: 5,000–7,000 lux
• Vegetative growth: 15,000–50,000 lux
• Flowering: 45,000–65,000 lux
• Maximum recommended amount of light: 75,000 lux

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Hope that proves to be helpful/useful information.

HLG had a blog post (I think on their website) indicating that their lights have a lux -> par conversion of 0.015. Very helpful. I use the DrMeter lux meter also, and am very happy with it. I find the “%” guessing on the dimmer is tricky, so I like being able to measure lux directly (and have a reasonable conversion to par).

 

[pop22]

I've no idea. But I estimate them at around 60%+ efficiency so 160 watts is heat at the heatsink, so about 546 BTU/hr.

Do you know the BTU's the Diablo is putting off at 70% of full power?

 

[pop22]

Alright, I'm getting , according to my cheap PAR meter, an average of 800 PPF at 24" under the light. And that's where I'm trying to keep my light

Running lower power for seedlings is ok, it's really about saving some power consumption. I personally wouldn't go below 200 watts. Look at it this way, my beans that just sprouted under full June sun light which is what 1500 PPFD? so run it soft and drop it low for seedlings

 

[Dreminem169]

HLG had a blog post (I think on their website) indicating that their lights have a lux -> par conversion of 0.015. Very helpful. I use the DrMeter lux meter also, and am very happy with it. I find the “%” guessing on the dimmer is tricky, so I like being able to measure lux directly (and have a reasonable conversion to par).

Those dimmers are super sensitive, I have a killawatt plugged into mine and just the slightest movement can jump the wattage by 100 But towards the end of the dial it’s not sensitive at all. Super strange… I would highly recommend a killawatt as well. Just for reference

 

[Silver]

HLG themselves have a guide for the different stages of plant growth.

The chart is for reference only. Plant response may vary due to plant types and environmental conditions.

Seedlings, Clones	Under 100 PPFD
Veg, Greens	150 PPFD - 400 PPFD
Extended Veg with healthy plants	350 PPFD to 500 PPFD
Flowering, Fruits	400 PPFD to 800 PPFD
Flowering with Supplement CO2	600 PPFD to 1100 PPFD

It also has a very helpful calculator which converts Lux to PPFD, you can view it on their official website here ;

Converting Lux to PPFD & Measuring Lux with Smartphone

Spectrometer and Quantum Sensor can cost hundreds to thousands of dollars and not every grower can afford them. A Lux meter app on phone can be used to ensure even light spread across canopy and give estimate of Lux. Use a calibrated Lux meter for better accuracy. Just divide the Lux value you...

horticulturelightinggroup.com

 

[Les @HLG]

That's what I use to adjust my lights. I built mine with dual drivers so the meter is the only way to to keep the output balanced for me.
I'm not familiar at the moment with Invertronics drivers, ut they likely can use PWM dimmers which are around $25 for precise control. I'll look into it.

Those dimmers are super sensitive, I have a killawatt plugged into mine and just the slightest movement can jump the wattage by 100 But towards the end of the dial it’s not sensitive at all. Super strange… I would highly recommend a killawatt as well. Just for reference

 

[Les @HLG]

And sorry, I was having trouble logging in earlier.

 

[Les @HLG]

Here you go! 10% discount code for AFN members! Code AFN

 

[tronN00dles]

Just to add to this lux/PPFD stuff, my approach is as follows. Note, I’ll avoid posting actual numbers to encourage people to do some research to essentially find what numbers work best for their particular situation.

My understanding is that PPFD numbers are well established for the various growth stages of cannabis. Look these up and you’ll see relatively consistent numbers, i.e., 800 PPFD shows up a lot. This is a number I use myself to guide my lighting requirements. The caveat I’m faced with, however, is DLI. Another number you’ll see a lot is 40-45 DLI. My struggle is PPFD guidelines typically serve photoperiod growers doing 18/6 during veg and 12/12 during flower. Fortunately, I believe that DLI is the key to converting PPFD to Lux, which is a cheaper metric to measure .

As such, my current approach, which has been serving me well, is do to the following:

1. Find PPFD requirements for the various growth stages of cannabis cannabis;
2. Use PPFD to DLI conversion charts, by light cycle duration, to find the DLI that corresponds to your desired PPFD. So based on your light cycle, e.g, 20/4, 24/0, 18/6, etc, convert your desired DLI to your desired PPFD.
3. Look up PPFD to LUX calculators, preferably specific to your light temperature in Kelvins, to find LUX requirements.
4. Use cheap LUX meter to calibrate light height and/or wattage. Careful, as LUX to PPFD calculators will depend on the physical qualities of your light and are not all equal. Fortunately HLG provides calculators specific to their lights!

Happy growing,

tronN00dles

 

[Les @HLG]

I believe the DLI for Cannabis is closer to 60 DLI

Just to add to this lux/PPFD stuff, my approach is as follows. Note, I’ll avoid posting actual numbers to encourage people to do some research to essentially find what numbers work best for their particular situation.

My understanding is that PPFD numbers are well established for the various growth stages of cannabis. Look these up and you’ll see relatively consistent numbers, i.e., 800 PPFD shows up a lot. This is a number I use myself to guide my lighting requirements. The caveat I’m faced with, however, is DLI. Another number you’ll see a lot is 40-45 DLI. My struggle is PPFD guidelines typically serve photoperiod growers doing 18/6 during veg and 12/12 during flower. Fortunately, I believe that DLI is the key to convert PPFD to Lux, which is a cheaper metric to measure .

As such, my current approach, which has been serving me well, is do to the following:

1. Find PPFD requirements for the various growth stages of cannabis cannabis;
2. Use PPFD to DLI conversion charts, by light cycle duration, to find the DLI that corresponds to your desired PPFD. So based on your light cycle, e.g, 20/4, 24/0, 18/6, etc, convert your desired DLI to your desired PPFD.
3. Look up PPFD to LUX calculators, preferably specific to your light temperature in Kelvins, to find LUX requirements.
4. Use cheap LUX meter to calibrate light height and/or wattage. Careful, as LUX to PPFD calculators will depend on the physical qualities of your light and are not all equal. Fortunately HLG provides calculators specific to their lights!

Happy growing,

tronN00dles