Growing phals under 65w 'grow lights' vs. led ??

[greenpassion]

Someone had told me that phals would not make it if grown under regular 'grow' bulbs. Does anyone know if this is true? Mine are around 2 1/2 ft away from 4 track light heads with the common Sylvainia 'grow' bulbs in them. I was told that I had to use MR16 bulbs, but they don't have a screw base for the track heads. Can't I use any other led bulb that could work with the track heads? Is the issue LED or what??

[quiltergal]

The jury is still out on LEDs and how effective they are. They are still very expensive.

If your Phals are 24+ inches from the lights then the lights aren't doing them much good. Mine are only 6 inches or less from the lights. I'm using inexpensive T5 high output lights.

[Gage]

I know it would be practical to use the track lights for the Phals, but I'm afraid incandescent lights won't provide what most plants need. As Quiltergal said, T5's are the way to go for grow lights. I just get my fixtures from Home Depot and order bulbs from buylighting.com, making sure to get something like 6500k or higher. There are all kinds of fantastic grow light setups out there, but this is truly the cheapest route I have found for a simple Phal setup (something like $45 total I think, for a 3', 2 bulb setup, which is enough for small Phals).

[King_of_orchid_growing:)]

As far as a florescent bulb's Kelvin temperatures go - I recommend somewhere in the range of 5500 K - 7200 K, any higher than 7200 K gives off too much light in the blue wavelength.

The lights that give off more blue are not designed for growing terrestrial, lithophytic, or epiphytic plants. They are designed for the zooxanthellae of corals that come from deep reef zones.

Zooxanthellae are symbiotic dinoflagellates that live on or inside the tissues of live corals.

[terryros]

My Phals are growing successfully under MR16, 7 watt, 38 degree dispersion LED lights bought from Orchids Limited. They are 30 inches above the growing zone and 12 inches apart over a growing area. Yes, they are initially expensive, but they last much longer and consume less electricity so over the longer term you can even come out ahead.

[greenpassion]

Originally Posted by terryros

My Phals are growing successfully under MR16, 7 watt, 38 degree dispersion LED lights bought from Orchids Limited. They are 30 inches above the growing zone and 12 inches apart over a growing area. Yes, they are initially expensive, but they last much longer and consume less electricity so over the longer term you can even come out ahead.

Thank you Terryros. I had checked out the MR16 bulbs, which look good to me, but then I thought I could look around for the same bulb elsewhere, may be less expensive. As I searched, I learned that the MR16 bulb is like many other LED bulbs, and it's the base (2 pins) that actually make it the MR16. An LED bulb with the screw base is essentially the same thing. So I'll look for an LED bulb, 7watt, 38 degree spread.

[msaar]

Let's not get too loose with terminology. A true MR 16 lamp is an incandescent quartz lamp with an integral reflector, like a slide projector lamp. MR stands for "multi-faceted reflector" and 16 is the reflector diameter in eighths of an inch (2"). They are mostly low-voltage (12V) but generate a tremendous amount of heat.
I looked at the info at orchids limited; they claim 3 7W led lamps will replace 4 48" fluorescent lamps. The output of the 7W lamps is 700 lumens x 3=2100 lumen total output. 48" F32T12 cool white fluorescent lamps output 2700 lumens X 4= 10400 lumens. Granted that the 3 led lamps provide 100% of the light on target, the fluorescent fixture would have to direct only 20% of its light to the target (plants) as the leds to be equivalent. The fluorescent lamp is rated for a longer life than the leds, but for simplicity's sake, let's say they're equal. Now costs. 4 fluorescent lamps are $6 ea x 4= $24 plus say $25 for a fixture = $49. 3 leds@ $70 = $210. First cost difference is $161. Assuming 20000 hours life, electrical savings needs to be .8 cents/hour to break even. 128W - 21W = 107W per hour savings @ $.20/KWH = roughly $.02/hour savings. Feel free to question my math (I didn't use a spreadsheet), but the numbers just don't work for leds vs. fluorescent yet.

[terryros]

The math obviously depends on the inputs. For example, I have always used wide spectrum fluorescent lights and never found them anywhere ner $6. Also, I haven't seen any fluorescent lights that anyone recommended to provide constant illumination for 3+ years. Most have recommended changing yearly. Finally, lumens don't tell you everything because you don't know the wavelengths the lumens were measured. What matters is the amount of illumination at the wavelengths the orchids need to grow and bloom. I am able to grow and blood Phals, Phrags, Catts, Paphs, Miltoniopsis under the LED lights.

However, I did not change to LEDs to save money. Even if the cost had been equal and the growth and blooming had been equal I would have changed to gain two important things for an indoor grower: headroom over the plants and control of temperature. With my plant room full of fluorescents/compact fluorescents, as soon as many things began to spike, the lights had to be raised and the illumination of the plants fell. Caring for the plants with the lights much higher than with fluorescents is also easier. The fluorescent lights also generated a large amount of heat, causing me to need to open the plant room door to the house lower level, thus losing humidity and putting unwanted heat into the house. With the LEDs, I have plenty of height over the plants for spiking and have complete control of temperatures in the room.

[msaar]

There are all kinds of reasons that go into decisions, and I'm not questioning yours. . I'm having trouble believing that three 7W leds will replace 4-48" fluorescents. The photometric diagram of the 7W 38d lamps indicate 1600 lux at 1 m, or about 160 fc @ 39", covering a .69 m (26") circle. Based on your spacing/distance, you are providing a 50% overlap, so your brightest area should be about 400 fc. Am I anywhere close to what you are getting on the foliage?
(BTW, lifetimes for F32T8 5000K lamps are rated from 20,000 to 40,000 hours, and priced from $4 to $8)

[terryros]

I use three different types of LED lights. The MR16 7 watt with a 38 degree dispersion lens, a BR30 15 watt, 60 degree dispersion, and a BR30 15 watt, 120 degree dispersion. By calculations using lumens data at various heights from the company (and a little geometry), I use the following heights and should be getting the following fc under the lights. I chose the heights to create about 21 inch wide cones of light. I space lights enough apart to have half of each growth area be double in illumination because of overlap:

MR16, 7 watt, 38 degrees: 30 inches high; 246 fc
BR30, 15 watt, 60 degree: 18 inches high; 261 fc
BR30, 15 watt, 120 degree: 6 inches high; 735 fc

I use different plants under the different lights, depending on the heights of spikes. Obviously, the third type would be for things like Catts that need higher light and have spikes that don't go too high about the leaves. I use the first type for tall spiking plants like Phals and Phrags.

Orchids Limited now has a number of growers using these lights successfully, even though you might think the amount of illumination seems low. However, since this is steady illumination throughout the day and the wavelengths of the natural white bulbs seem good for growth/blooming, there appears to adequate illumination for all the genera of orchids that I grow.

I think a number of others through the years have commented that our traditional fc numbers for different genera are really noting the peak fc occurring during natural daylight in the wild or in greenhouses. However, much of a day you do not have this same peak light and it appears that you can be successful with lower and steady illumination, particularly if the wavelengths are correct.

I believe that Jerry Fischer of Orchids Limited is in the process of preparing an article on the use of LED lights for an upcoming edition of Orchids from the AOS.