LED lights and PAR w/ Paphs&Phrags

[shade131]

I know this won't apply to a lot of people who use good ole sunlight....

I tried searching this site but the search functions rejects "LED lights PAR" and most variations thereof. So apologies if this info is already on the site - I tried.

I use LED's exclusively for now. I think they're generally fantastic technology. What scant information is out there online about growing orchids under LED lights (99% is, of course, about growing weed) suggests that the ideal PAR is around 100 (umoles m-2 s-1) for paphs. I was a little stunned by this, as I estimate mine are getting from 150-400 at 20-24" under a 450w grow light. Huge range, I know. It's a very rough estimate, and I finally bit the bullet and ordered a PAR meter.

Anyway, if anyone out there is using LED's and would like to compare notes, as far as I can tell there is very little hard data aside from one study on P. insigne. So any information or experience would be very valuable to me.

One vexing development I'll throw out there:

The following species/hybrids burned to varying degrees: callosum, Gloria Naugle, delenatii (v.dunkle), Ho Chi Minh, Deperle and Phrag. Eric Young...Notably, culturally similar ones right next them - other parvi, brachy and multis - did not.

I can't make any sense of the Gloria Naugle or the Phrag burning when other supposedly lower light paths didn't burn. Maybe I pulled them out of the shipping box and into the light too quickly and it shocked them? Just a weird individual? Otherwise, many of the others have some delenatii in them, so l guess delenatii might be more sensitive than others with PAR?

So, like I said, any and all people out there using LED's, your experiences and expertise would be greatly appreciated!

Brandon

 

[Duck Slipper]

I agree Brandon, I also did a search and didn't get much info on LED's. I think it is just a new form of gro light and many people are already successful using T5, T12, MH, HPS. I recently purchased 2- 6 bulb T5's. But, I made that purchase because I already was successfully using T12's and considered the T5's an improvement. I just couldn't read enough about LED's, to purchase them. Not to mention the variations of LED available and which to purchase. Dan

 

[terryros]

I have grown and bloomed my Phrags successfully under LED lights for about 5 years. I don’t grow many Paphs. Of course I have been tweaking potting mix and nutrition over this period of time, but I have kept the PAR reading at 80-100 at the leaf tops. My LEDs have a focused light beam of 40 degrees and a little data suggests that this more vertical light reduces the required intensity needed for photosynthesis. My Phalaenopsis receive only about 50 with the same 40 degree bulbs while my Cattleyas are given between 250-400 (depending on the species) at the leaf tops using 60 degree angle focused bulbs.


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[shade131]

I agree Brandon, I also did a search and didn't get much info on LED's. I think it is just a new form of gro light and many people are already successful using T5, T12, MH, HPS. I recently purchased 2- 6 bulb T5's. But, I made that purchase because I already was successfully using T12's and considered the T5's an improvement. I just couldn't read enough about LED's, to purchase them. Not to mention the variations of LED available and which to purchase. Dan

Duck - thanks for the thoughts. I hear you. The technical specs get mind-numbing pretty quick with LED. One significant advantage of fluorescent tubes is they lend themselves to stacking much more than your run of the mill hanging LED rectangle. If I had it to do over I might’ve gone with a series of long strips of LED so I could keep the intensity down at close range and still keep the lights relatively close to plants. And grow more plants in the same vertical space....On the other hand, having lights far away from plants makes tall spikes much easier to deal with.

 

[shade131]

I have grown and bloomed my Phrags successfully under LED lights for about 5 years. I don’t grow many Paphs. Of course I have been tweaking potting mix and nutrition over this period of time, but I have kept the PAR reading at 80-100 at the leaf tops. My LEDs have a focused light beam of 40 degrees and a little data suggests that this more vertical light reduces the required intensity needed for photosynthesis. My Phalaenopsis receive only about 50 with the same 40 degree bulbs while my Cattleyas are given between 250-400 (depending on the species) at the leaf tops using 60 degree angle focused bulbs.


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I have grown and bloomed my Phrags successfully under LED lights for about 5 years. I don’t grow many Paphs. Of course I have been tweaking potting mix and nutrition over this period of time, but I have kept the PAR reading at 80-100 at the leaf tops. My LEDs have a focused light beam of 40 degrees and a little data suggests that this more vertical light reduces the required intensity needed for photosynthesis. My Phalaenopsis receive only about 50 with the same 40 degree bulbs while my Cattleyas are given between 250-400 (depending on the species) at the leaf tops using 60 degree angle focused bulbs.

Terry - that’s helpful, thanks! I’m definitely running my phrags too bright it seems. Burned leaves are the worst, just ruins the appearance of my otherwise healthy blooming phrags. ....I’ve come across similar information for beam angle. It’s still very much uncharted territory, especially regarding orchids. What’s exciting to me is that - theoretically - the ability to customize wavelength, intensity, and duration should ultimately give LED an advantage over any type of artificial lighting, and even sunlight. Long ways away, but a lot of the agricultural research using vertical LED farms for produce is very encouraging. Great yields, very low cost of production since LED use little electricity, water, fert and humidity can all be controlled precisely, etc....but I digress

What sort of LED are you using? I use 300w and 450w viparspectra fixtures that I’ve been pleased with, although the 450 is stronger than it needs to be. Have you had good results with growth and blooming the different types? My Phal’s have responded better than anything 2 years in.

Brandon

 

[xiphius]

Another consideration with the LED vs tubes is intensity for area of coverage. A lot of the dedicated LED grow lights out there are small and boxy. This creates a relatively high-intensity light that covers a small area. Tubes that are 4ft long cover a larger area at lower intensity. The bulk of my orchids are in a grow tent under a 300W LED light that 3-4 ft from the plants and I feel like it is on the cusp of being *too* intense for plants directly underneath it. The ones on that side of the tent tend to run a bit more yellowish green than I would like (but still grow well). At some point I will probably replace it.

In that respect, those types of LED lights aren't great for a large-ish collection unless you can mount them really high over the plants since they don't cover a very large area relative to tubes (and are much more expensive).

That said, I really like LEDs and feel they are future of growing under lights. I have been really happy with how they have grown my orchids.

I haven't taken measurements myself (don't have a meter), but the light I have is rated around ~100 umol/m^2/s at around 36 in distance (remember that PAR ratings are going to be highly distance dependent... closer obviously = higher).

 

[terryros]

I have always used ALT LED lights that I obtain from Orchids Limited in Minnesota. These bulbs screw in to track lighting fixtures. My 40 degree angle bulbs are 7 watt MR16 bulbs and my 60 degree bulbs are either 15 watt or 20 watt bulbs. All of these bulbs have superior heat dissipation design. I can easily touch and untwist the bulbs when they have been turned on for hours. The key part of this is that bloom spikes can be fairly near to these bulbs without damage. I can have the MR16 40 degree bulbs at least 2 feet above the leaf tops with Phals and Phrags which accommodates the great majority of spikes. The 60 degree bulbs can be at least 6-8 inches above Cattleya leaf tops so accommodate most spikes.

Yes, these bulbs are more expensive than many you can find, but I think I am getting what I am paying for - the beam angle, the heat dissipation, the consistency. I have had very few failures in the bulbs and they maintain their illumination for years.


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[gego]

I measured mine in foot candles and use 900 to 1200 FC for flowering sizes, 400-800 for seedlings depending in size.
I noticed an adjustment period if they came from natural light. So newly moved plants will get lower intensity first until new leaves come out. If I don't do that, leaves will turn yellowish even though they had the same FC from natural light.
I noticed the new leaves coming out are darker green, like they adjusted to the new source and started to grow again.
And maybe because the intensity is constant unlike natural light, older leaves started to turn yellowish on the matured plants. I increased my fert strength and the yellowing stopped and some of them started to turn green again.
Dont know if the measurements from natural and LED is apple to apple. I just use them for reference and just observe the plants then adjust accordingly.
One thing for sure,,,,when using LED for the first time,,,, start from a low intensity,,, meaning more distance to the leaves then lower the source gradually.

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[Ray]

I noticed an adjustment period if they came from natural light. So newly moved plants will get lower intensity first until new leaves come out. If I don't do that, leaves will turn yellowish even though they had the same FC from natural light.

I don't know if It applies in your situation, but many folks don't realize that they are giving their plants way too much light under any artificial source when compared to natural lighting.

The progression of natural light from dawn to noon to dusk provides half the volume of photons to the plant than does artificial light at that same peak intensity (which is what most culture sheets provide) kept on for the same duration.

 

[gego]

I don't know if It applies in your situation, but many folks don't realize that they are giving their plants way too much light under any artificial source when compared to natural lighting.

The progression of natural light from dawn to noon to dusk provides half the volume of photons to the plant than does artificial light at that same peak intensity (which is what most culture sheets provide) kept on for the same duration.

Agree. And that should be taken into considerations. Also it has a different source of wavelengths but i noticed they adjust as they grow. Some LED,,, expensive ones provide the broad spectrum,,,I think it is worth it. They keep for a long time
I actually have multiple bulbs arranged about 45 degrees from the plants on booth sides. Then I use timers to mimic morning, noon and afternoon. Spikes can go up unrestricted.

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[shade131]

Really appreciate all the information. Over the last few days I’ve slowly been coming to the realization that I have way more lighting than I need. I’ll be able to get hard data when my PAR meter shows up, but I’m pretty confident that I’m growing paphs under dendrobium or cattleya light levels. I’m going to have to completely overhaul my setup to be able to hang the lights higher. What’s interesting is that while I noted that several burned (largely delenatii or its hybrids - I thought parvis would be less likely to burn?) 80% are doing really well. Maybe a few here or there that are a bit bleached out, but many have spiked. Watering a good bit, Humidity 50-70%, temp 55-70, and a ton of airflow. Maybe all that adds up to them tolerating more light than normal. I’ll post some pictures later. Have a good weekend everyone.

 

[shade131]

Agree. And that should be taken into considerations. Also it has a different source of wavelengths but i noticed they adjust as they grow. Some LED,,, expensive ones provide the broad spectrum,,,I think it is worth it. They keep for a long time
I actually have multiple bulbs arranged about 45 degrees from the plants on booth sides. Then I use timers to mimic morning, noon and afternoon. Spikes can go up unrestricted.

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This sounds like a great idea. Solves the spike dilemna and encourages symmetrical growth.

 

[gego]

Really appreciate all the information. Over the last few days I’ve slowly been coming to the realization that I have way more lighting than I need. I’ll be able to get hard data when my PAR meter shows up, but I’m pretty confident that I’m growing paphs under dendrobium or cattleya light levels. I’m going to have to completely overhaul my setup to be able to hang the lights higher. What’s interesting is that while I noted that several burned (largely delenatii or its hybrids - I thought parvis would be less likely to burn?) 80% are doing really well. Maybe a few here or there that are a bit bleached out, but many have spiked. Watering a good bit, Humidity 50-70%, temp 55-70, and a ton of airflow. Maybe all that adds up to them tolerating more light than normal. I’ll post some pictures later. Have a good weekend everyone.

There is a Lux light meter app,,, it is free. It works well. May not be very precise but it gives you a good reference and the reading is consistent. That is all that matters.

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[masaccio]

Overlighting?

Hm. This is on the heels of having just read Ray's comment above that many of us don't realize we're over-lighting with artificial light. I have a long window ledge that I've fitted with a line of LED spotlights. They're not special grow LEDs, just Sylvania home-use spotlights that were recommended by a trusted source for orchids. They're rated at 25 watts, 250 watt equivalent. 2650 Lumens. I don't really speak "lumen" but maybe some of you do. (Growth flowering and rooting all good, for the most part.) I worry if my par meter goes under 300 umols for anything. For most plants its between 400 and 500 or higher. I'm beginning to think that I'm grossly overlighting my orchids based on what I'm reading here. I have various paphs (a couple of brachys, a warm multifloral and a complex hybrid, also phals, a cattleya seedling. I have noticed some tendency of "purple-izing" and a little paling. Maybe its time to pull them up. (Ya think?) Also maybe will run them 12 hours a day instead of 14? It sounds like I should be going for between 100-300 umols ? I think my LED skepticism maybe got the better part of my judgment. The pic represents the setup except there are eight lights now instead of five. I did this to get more even coverage between fixtures. But if I raise them up, the coverage could even out and I could do with fewer fixtures as well.

 

[gego]

Gaging from the distance and the wattage of the bulb,,, you are definitely overdoing it. The intensity and the duration will add up.
I good gage is a Lux meter I stated above, you can down load the app for free. Set the units as Foot-Candles. With your phone, you can gage how much light your plant is receiving. For big multi,, 900-1100 FC is a good number. Since these bulbs have lenses, the constant intensity of the light striking the same spot on the leaf can actually make a burn. So blowing air is needed. I would not be surprised if those leaves are subjected to 2000-3000 FC measured using the app.
Goodluck

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[Ray]

If this is a repetition of formerly posted info, I apologize.

Another LED "Oops" is replacing fluorescents with LEDs having the same output and having them at the same distance from the plants.

A fluorescent tube radiates in all directions, and no matter how good the reflector, much less than 100% of the light reaches the plants. With many LEDs, a much greater percentage is radiated toward them, with spot and flood lights approaching 100%.

 

[masaccio]

Gaging from the distance and the wattage of the bulb,,, you are definitely overdoing it. The intensity and the duration will add up.
I good gage is a Lux meter I stated above, you can down load the app for free. Set the units as Foot-Candles. With your phone, you can gage how much light your plant is receiving. For big multi,, 900-1100 FC is a good number. Since these bulbs have lenses, the constant intensity of the light striking the same spot on the leaf can actually make a burn. So blowing air is needed. I would not be surprised if those leaves are subjected to 2000-3000 FC measured using the app.
Goodluck

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Really? I'm not knowledgeable about paphs, but I thought those roth-type multiflorals liked cattleya-level light. Maybe you were speaking of another type of multi? Or maybe my info is outdated. OR, (maybe I'm getting this) the number is lower because, as Ray pointed out, they're getting that consistent level of FC for several hours all day, every day. Yes?

 

[gego]

Yes. Even catts will burn if the angle is just right. Anyways, it is better to not guess by measuring. That's just my opinion since you showed us your set up. I did not mean you dont know your plants.
Good luck.

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[shade131]

So I got I my PAR meter and I can confirm that they were all getting a minimum of 220, all the way up to 400. Unfortunately, I could only raise the lights a few inches, but that got it down to 140-300. Given that the majority were doing well under very high light, I *think* I should be fine now. I think good airflow and humidity can raise their threshold. I’d also speculate that the tiny bit of info out there claiming that you should never go above 150-200 for ANY Paph is misguided.

If any of you growing under LED have similar concerns, Amazon has a PAR meter for $100usd that justified its price after about 30 seconds of use. Very handy.

 

[Ray]

If any of you growing under LED have similar concerns, Amazon has a PAR meter for $100usd that justified its price after about 30 seconds of use. Very handy.

Which one did you get?