Move lights further away or drop intensity?

I have a set of Migro array 4 LED lights. I have been super happy with them overall and highly recommend them.

The website says that they should hang 8" above the plant. When I do that, I get signs of light stress. I can either raise them a few inches up, or dial back the intensity of the lights. Which is the better option for the plants/yield? I grow with a scrog and have a pretty even canopy if that makes a difference. I'm finishing up week 3 of flower currently

You will save on electricity costs by turning the light down, but by keeping intensity high and moving the light away instead is better for light penetration (or so I’ve been told)

adam2706 said:

I have a set of Migro array 4 LED lights. I have been super happy with them overall and highly recommend them.

The website says that they should hang 8" above the plant. When I do that, I get signs of light stress. I can either raise them a few inches up, or dial back the intensity of the lights. Which is the better option for the plants/yield? I grow with a scrog and have a pretty even canopy if that makes a difference. I'm finishing up week 3 of flower currently

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Move them up a little. I would see how you go at 12inches. Got a link to the light?

adam2706 said:

I have a set of Migro array 4 LED lights. I have been super happy with them overall and highly recommend them.

The website says that they should hang 8" above the plant. When I do that, I get signs of light stress. I can either raise them a few inches up, or dial back the intensity of the lights. Which is the better option for the plants/yield? I grow with a scrog and have a pretty even canopy if that makes a difference. I'm finishing up week 3 of flower currently

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Buy a PAR meter. If you are going to use LED it's a great investment. And it doesn't need to be an Apogee. I checked my cheapo side by side with the neighbor's high dollar Apogee and the differences in readings were so close it blew his mind. Under $150 on Amazon. Not the Hydrofarm Lux meter but a PAR meter.

Then avail yourself of the videos by Dr Bruce Bugbee on YouTube. This is my only YouTube recommendation.

ballist said:

Move them up a little. I would see how you go at 12inches. Got a link to the light?

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I'm giving the 12in a try now, I just wasn't sure if someone more experienced than me has tested both options to see which is best.

Here is a link to the manual for my lights. I have the 4 light option pro + red

I would think intensity is better to change because if the lights are to high the plants could 'stretch' more towards the light, but that also happens with not enough intensity so either way will work to some degree...keep changing each until you find the 'sweet spot'.

Mak'er Grow said:

I would think intensity is better to change because if the lights are to high the plants could 'stretch' more towards the light, but that also happens with not enough intensity so either way will work to some degree...keep changing each until you find the 'sweet spot'.

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Or buy a meter and know immediately.

If you have an iPhone Photone works very well for me .
It has to be calibrated, but if you have manufacturers ppfd its easy and cheap.

The feel with my girls , was further away with it on full.

I like to leave my intensity alone and just raise it as high as I can during veg-it's the perfect amount of light for me. I don't use a PAR meter, just a cheap but accurate lux meter and it helped dial in my distances immensely. I see a lot of deficiencies in pictures here when people are vegging their plants at 40% or whatever. They grow weird looking big leaves and seem really sensitive to normal PPMs of nutrients. Of course you need to be careful not to bleach them, and you might need to harden off your seedlings anytime you increase the light, but you'll grow much better structure and canopy when you give them plenty of light in veg.

adam2706 said:

I'm giving the 12in a try now, I just wasn't sure if someone more experienced than me has tested both options to see which is best.

Here is a link to the manual for my lights. I have the 4 light option pro + red

MIGRO ARAY - Instruction Manual & Datasheet

Download the ARAY operations manual here

www.migrolight.com

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Thanks, I took a quick look and these are light bar type. These generally spread the light. The other possibiliy is under feeding plant

hotrodharley said:

Buy a PAR meter. If you are going to use LED it's a great investment. And it doesn't need to be an Apogee. I checked my cheapo side by side with the neighbor's high dollar Apogee and the differences in readings were so close it blew his mind. Under $150 on Amazon. Not the Hydrofarm Lux meter but a PAR meter.

Then avail yourself of the videos by Dr Bruce Bugbee on YouTube. This is my only YouTube recommendation.

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Is the Phot*Bio by phantom the cheapo meter you recommend?

Wayne55 said:

Is the Phot*Bio by phantom the cheapo meter you recommend?

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It's this critter. There's a YouTube video the Apogee owner sent me comparing the 2 meters. For the minor difference in readings I'll take it over the expensive Apogee. I'm not recommending this cheap unit over the Apogee. But if you are going LED I strongly recommend one. I bleached some seedlings ivory white with another LED. Literally looked like carved ivory. Never seen anything like it. I bought the meter that day

smokey0418 said:

If you have an iPhone Photone works very well for me .
It has to be calibrated, but if you have manufacturers ppfd its easy and cheap.

The feel with my girls , was further away with it on full.

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After I bleached those seedlings I duplicated the setup after getting the meter. I had set the light up per recommendation in the instructions. Measured over 400! Seedlings should be about 250 at most.

further away

Raise lights. If you have room to do so. Could go 16x8 schedual too.

smokey0418 said:

If you have an iPhone Photone works very well for me .
It has to be calibrated, but if you have manufacturers ppfd its easy and cheap.

The feel with my girls , was further away with it on full.

Click to expand...

That’s what I use. Best $6 I ever spent.

hotrodharley said:

After I bleached those seedlings I duplicated the setup after getting the meter. I had set the light up per recommendation in the instructions. Measured over 400! Seedlings should be about 250 at most.

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I also have been keeping my lights on the edge of yellow try doing exactly what this person asked.

Using the Photone app (8.69 just a few weeks back)
Has been the best by far . After I calibrated 1120 at 18 inch off my lights I have checked numerous times again and it very close to what I set.
I get ppfd and dli in a swipe for 9 bucks .
I’m in .

These plants I have now in early flower have a difficult time at anything more than 600.

I struggled for a bit then was on cruise control, turned the lights and boy did things change.

Having this for the very small price imho is a no brainer.

I spent more on clay rocks.

Just use your phone it's close enough download tent buddy set it to the spectrum of your light and go from there.

I run more light than a lot in veg I personally like my vegging plants at 500-800.

TLDR version: if you have a large fixture (lots of LEDs) turn them down and hang them closer. If you have a small fixture, hang it higher for better (more even) canopy coverage.

We compared the Photone Ap against a $1600 hand-held spectrometer (Lighting Passport) and as long as you covered the phone camera with a piece of white paper to diffuse the light, it was quite accurate.

Lifting the light
Pros: Easy to do, easy to reference (by distance from plant canopy); can give a fairly uniform coverage of light over the canopy
Cons: Wastes energy and light; doesn't reduce heat in the grow area; may run out of head height; usually reduces penetration due to wasted light and wall losses

Reducing intensity
Pros: Increases efficiency of the LEDs; reduces energy usage and heat; usually increases penetration by increasing the angles of available light that can penetrate through and under the foliage; increases life of LEDs
Cons: Lights must be constantly adjusted for growing plants (easier for plants to grow into the LEDs); reduces light footprint, which can create uneven canopy lighting if the fixture is small and the canopy area is large

Light meters are great, but every plant is different and some respond better to higher levels of light than others (sativas vs indicas for example). For that reason, a simple Watt meter (also known as an energy cost meter or wall meter) can be invaluable for setting up your lights by simply turning them down to a suitable wattage until your plants are happy, and using that wattage reading as a reference for each time you need to turn the lights up and down.

adam2706 said:

I have a set of Migro array 4 LED lights. I have been super happy with them overall and highly recommend them.

The website says that they should hang 8" above the plant. When I do that, I get signs of light stress. I can either raise them a few inches up, or dial back the intensity of the lights. Which is the better option for the plants/yield? I grow with a scrog and have a pretty even canopy if that makes a difference. I'm finishing up week 3 of flower currently

Click to expand...

8 inches is too low with good lights... Get you a laser thermometer too. 16-24 has been my sweet spot. With my HLG 550, 24 inches was the sweet spot cause of heat and high PAR. With cheap vipar 16 was better.