LED Lighting - Intensity vs Duration/clarity
Login
User Name
Password   


Registration is FREE. Click to become a member of OrchidBoard community
(You're NOT logged in)

menu menu

Sponsor
Donate Now
and become
Forum Supporter.

LED Lighting - Intensity vs Duration/clarity
Many perks!
<...more...>


Sponsor
 

Google


Fauna Top Sites
LOG IN/REGISTER TO CLOSE THIS ADVERTISEMENT
  #1  
Old 02-04-2020, 09:27 AM
Clawhammer Clawhammer is online now
Senior Member
 

Join Date: Aug 2019
Posts: 245
LED Lighting - Intensity vs Duration/clarity
Default LED Lighting - Intensity vs Duration/clarity

Hello smart people... I've really only grown orchids under LED light panels and have had great results. I've never had a burn and have had success with reflowering most plants that I have attempted.

I use these lights and use a light meter to measure FC.
Robot Check

My catts get 2000-3000 fc under these lights, less than what is listed that they require, yet all new growth is highly pigmented, which in my understanding means they are receiving more than adequate lighting. I've rebloomed most of the catts under these lights.

Finally my question: How do we think about duration and clarity alongside FC? My plants under LEDs never get shaded, never experience a cloudy day, never get burnt despite being exposed to direct light for however long I wish them to be. How much does this compensate for the intensity not being the same as an hour of direct sun in the morning?
Reply With Quote
  #2  
Old 02-04-2020, 03:08 PM
thefish1337 thefish1337 is offline
Senior Member
 

Join Date: Dec 2013
Posts: 122
LED Lighting - Intensity vs Duration/clarity
Default

Quote:
Originally Posted by Clawhammer View Post
Hello smart people... I've really only grown orchids under LED light panels and have had great results. I've never had a burn and have had success with reflowering most plants that I have attempted.

I use these lights and use a light meter to measure FC.
Robot Check

My catts get 2000-3000 fc under these lights, less than what is listed that they require, yet all new growth is highly pigmented, which in my understanding means they are receiving more than adequate lighting. I've rebloomed most of the catts under these lights.

Finally my question: How do we think about duration and clarity alongside FC? My plants under LEDs never get shaded, never experience a cloudy day, never get burnt despite being exposed to direct light for however long I wish them to be. How much does this compensate for the intensity not being the same as an hour of direct sun in the morning?
DLI (Daily Light Integral) Chart - Understand your plants' PPFD & phot – Ledtonic

what you're describing is DLI. footcandles is an outdated and annoying metric still used in orchid culture guides. I grow many cattleya types at 200-250 ppfd = 1000-1250 fc and they bloom and show pigmentation. i use a photoperiod of 12 hours.
Reply With Quote
Post Thanks / Like - 1 Likes
Likes Clawhammer liked this post
  #3  
Old 02-04-2020, 03:45 PM
Ray's Avatar
Ray Ray is offline
Senior Member
 

Join Date: May 2005
Location: Oak Island NC
Posts: 11,520
LED Lighting - Intensity vs Duration/clarity Male
Default

1) Light meters are notoriously bad at measuring the output of LEDs. Unless yours is intended specifically for that application, your readings aren't telling you as much as you may think. Hence the apparently low intensity and pigmentation.

2) When you see a foot-candle recommendation, that is the peak, noontime intensity to which they may be exposed. Under artificial light, the intensity need only be about 50% of that to match the same DLI. READ THIS
__________________
Ray Barkalow, Orchid Iconoclast
Want Better Plants? READ THIS
firstrays.com

Free Shipping in the US! (see terms & conditions for details)
Reply With Quote
Post Thanks / Like - 1 Likes
Likes Clawhammer liked this post
  #4  
Old 02-04-2020, 03:52 PM
vvasabi vvasabi is offline
Jr. Member
 

Join Date: Jan 2020
Posts: 4
LED Lighting - Intensity vs Duration/clarity
Default

I second thefish1337ís comment. Footcandles/lumens/lux measure what human eyes see, and different artificial light sources can result in different intensity levels for photosynthesis even when the fc/lumens/lux values match. A better unit to measure light that plants use is PPF/PPFD, which actually measures the number of photons that drive photosynthesis. The equipments to measure PPF/PPFD are usually more expensive but will yield more reliable results.

Plants have specific DLI (total amount of light received in a day) ranges depending on various factors. Plants that need higher light levels have higher DLI requirements, and vice versa. Artificial lighting will definitely compensate the lack of, if not entirely replacing, natural light in terms of DLI. For cattleyas, this article suggests DLIs from 10 to 15.

Finally, you want to consider photoperiod (number of hours of light exposure in a day). While you can increase photoperiod to make up for the lack of high light intensity, it may be counterproductive and can result in various issues. 12 hours of light a day, which is what growers of medical plants do during the flowering phase, seems to be a safe bet for inducing flowering in other plants.

Hope this helps.

Edit: I was just looking at the link to the LED panel you are using, and the Amazon page actually shows a diagram with PAR levels (in PPF/PPFD) at different hanging heights. Assuming they are accurate-ish, these figures are very useful for you to determine the hanging height and photoperiod for your plants to achieve the desired DLI.

Last edited by vvasabi; 02-04-2020 at 04:20 PM..
Reply With Quote
Post Thanks / Like - 2 Likes
Likes thefish1337, Clawhammer liked this post
  #5  
Old 02-05-2020, 07:12 AM
Ray's Avatar
Ray Ray is offline
Senior Member
 

Join Date: May 2005
Location: Oak Island NC
Posts: 11,520
LED Lighting - Intensity vs Duration/clarity Male
Default

For most orchids, day length (photoperiod) is not critical. 12 on/12 off to as much as 16 on/8 off has worked fine for me. What's key is that the duration x the intensity stay within the preferred DLI range for the particular plant.

There are some cattleya species that rely on short days to trigger flowering, but outside of them, daylength sensitivity is fairly rare.
__________________
Ray Barkalow, Orchid Iconoclast
Want Better Plants? READ THIS
firstrays.com

Free Shipping in the US! (see terms & conditions for details)
Reply With Quote
Post Thanks / Like - 1 Likes
Likes Clawhammer liked this post
  #6  
Old 02-05-2020, 04:47 PM
Clawhammer Clawhammer is online now
Senior Member
 

Join Date: Aug 2019
Posts: 245
LED Lighting - Intensity vs Duration/clarity
Default

Thanks everyone, some very interesting learnings from this thread for me, especially about the effect of duration and how to translate the outside light requirement specs into something useful for growing under LED.

I was already familiar with the concept and measurement of PAR and would utilize it if the equipment wasn't cost prohibitive and there was a resource that had orchid species light requirements listed in PAR. Instead I was using FC to approximate PAR while know the spectrum of my grow light. I did not know however that my light meter was no good for measuring LED FC (thanks Ray).

Since I would rather buy more lights and orchids (and pay my mortgage) as opposed to a PAR meter I think I will just let the plants tell me if they are happy. Obviously flowering is the ultimate goal. Am I correct in assuming pigmentation is a good sign the plant is getting the right amount of light and leaf yellowing/browning is a sign of too much?

Last edited by Clawhammer; 02-05-2020 at 04:50 PM..
Reply With Quote
  #7  
Old 02-05-2020, 05:01 PM
thefish1337 thefish1337 is offline
Senior Member
 

Join Date: Dec 2013
Posts: 122
LED Lighting - Intensity vs Duration/clarity
Default

Quote:
Originally Posted by Clawhammer View Post
Thanks everyone, some very interesting learnings from this thread for me, especially about the effect of duration and how to translate the outside light requirement specs into something useful for growing under LED.

I was already familiar with the concept and measurement of PAR and would utilize it if the equipment wasn't cost prohibitive and there was a resource that had orchid species light requirements listed in PAR. Instead I was using FC to approximate PAR while know the spectrum of my grow light. I did not know however that my light meter was no good for measuring FC.

Since I would rather buy more lights and orchids (and pay my mortgage) as opposed to a PAR meter I think I will just let the plants tell me if they are happy. Obviously flowering is the ultimate goal. Am I correct in assuming pigmentation is a good sign the plant is getting the right amount of light and leaf yellowing/browning is a sign of too much?
since you're not noticing any flowering issues I'd say your current conditions are good. burning of leaves from too much photons is at the extreme end of exceeding your plants DLI. pigmentation may not give you the whole story. more light than nessesary increases demand for water, nutrients and co2 to sustain photosynthesis which can make it harder to keep up with your plants and leaves less room for mistakes. why not estimate the par at given heights from the amazon product listing and then use the chart I posted to put your cattleyas in the 10-15 DLI range? maybe they're already right. you know the par your light puts out at various distances and then you can estimate how much DLI your plants are getting from your light cycle. easy peasy
Reply With Quote
Post Thanks / Like - 1 Likes
Likes Clawhammer liked this post
  #8  
Old 02-05-2020, 05:07 PM
Clawhammer Clawhammer is online now
Senior Member
 

Join Date: Aug 2019
Posts: 245
LED Lighting - Intensity vs Duration/clarity
Default

Thanks once again for the guidance and for elaborating on why too much light can be harmful short of leaf burn.


Quote:
Originally Posted by thefish1337 View Post
since you're not noticing any flowering issues I'd say your current conditions are good. burning of leaves from too much photons is at the extreme end of exceeding your plants DLI. pigmentation may not give you the whole story. more light than nessesary increases demand for water, nutrients and co2 to sustain photosynthesis which can make it harder to keep up with your plants and leaves less room for mistakes. why not estimate the par at given heights from the amazon product listing and then use the chart I posted to put your cattleyas in the 10-15 DLI range? maybe they're already right. you know the par your light puts out at various distances and then you can estimate how much DLI your plants are getting from your light cycle. easy peasy
Reply With Quote
Reply

Bookmarks

Tags
catts, direct, led, light, lights


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Various interesting links about lighting. DavidCampen Growing Under Lights 12 02-23-2013 02:15 PM
Determining lighting intensity under fluro tubes for phalaenopsis OzPhal Growing Under Lights 29 08-05-2012 05:05 AM
What Lighting for Indoor Orchid Garden? seashells1990 Growing Under Lights 5 04-08-2010 06:38 PM
What Lighting for orchids? seashells1990 Beginner Discussion 9 03-02-2010 04:19 PM
T5 lighting intensity dennis4246 Beginner Discussion 7 02-01-2009 10:59 PM

All times are GMT -4. The time now is 06:36 PM.

© 2007 OrchidBoard.com
Search Engine Optimisation provided by DragonByte SEO v2.0.37 (Lite) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Feedback Buttons provided by Advanced Post Thanks / Like (Lite) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.

Clubs vBulletin Plugins by Drive Thru Online, Inc.