Does anyone use fixtures with T5H tubes/bulbs?

I just installed a couple of 4', six tube fixtures, and Holy Cow, what a difference in light intensity from my standard 6500K fluorescent fixtures. A comparison, at least the best I can do, is saying the cumulative light from four, 4', two-tube T8 fixtures would give the foot candles of a cloudless day at 4:00 PM and the light from a single, 4', six-tube T5H fixture would give the foot candles of a cloudless day at noon. Actually, the T8 bulb would emit 2900 lumens and the new T5H bulb would emit 5000 lumens. The difference is just remarkable.

It will be interesting to see whether I can tell any difference in my orchids' growth/blooming, since both new fixtures are in my Orchid Greenhouse.

My big light fixture is at its lowest point of the year today, but it will be brighter tomorrow.

Clouds may get in the way of its light, though.

I Ken, thank you, I was thinking about posting a question about lighting but don't even know the names of the different types of bulbs and fixtures. What do people use, that is, when the large fixture (the one Elaine uses) is not effective [2 hours of sunshine in at least 3 weeks].

I have a plant table (that seems to be its brand name ) and the lower shelf has a fixture with two "18 watt plant spectrum compact fluorescent tubes". These are now burnt out and I wasn't using the lower shelf for plants, but I need to replace it now and wondered if
1. A different make or type of bulb could be used (as long as the size is right, of course).
2. Is this the best available, practical for indoor use, artificial light available? I don't want to burn the plants!
3 . Has anyone used the Wonderlight wide spectrum light, which come in 100 and 300 watts. I don't know whether it is incandescent or fluorescent.
4. Any recommendations for artificial lights that can be used indoors and that won't use a huge amount of electricity?

First things first, Lore.

Fluorescent fixtures produce minimal heat, and the plants can be within a couple of inches of those bulbs. You can touch a "regular" fluorescent bulb and it feels slightly warm. Heck, I have had orchid leaves touching the bulbs without burn. However, those new T5H fixtures I just installed do produce heat, not a lot, but if you touch one of those bulbs, it is hot. Thus, I have positioned my plants about 6" from those bulbs. I am talking about the uppermost leaves. For me at least, that heat generated by the bulbs is beneficial. For November through March, I have to heat my greenhouse, so even a small amount of additional heat is good.

Fluorescent fixtures use very low wattage bulbs/tubes, so electrical consumption is very low. Of course the larger the fixture and the more tubes (2', 4', 6' bulbs and 2-bulb, 4-bulb, or 6-bulb fixtures) the more the electrical draw. But it is still minimal regardless of the size fixture. Those T5H fixtures use bulbs that are about twice the wattage as the same size T5 or T8 bulbs, but still, compared to incandescent bulbs, those fixtures are economical. If you have concerns about electrical cost, you can call your electric-service people, tell them what fixture you are using (they will need the total wattage of all the bulbs for example), and they can tell you how much it costs you to run that fixture per hour. You will be surprised how little it costs.

I don't know what that Wonderlight wide spectrum fixture/bulb is, but you can easily research that on the web. I assume, just by its name, that it will be in the range of 5000-6500K and a little research will give you the lumen output. As I previously said, if a T5, 6500 K bulb produces 2900 lumens per sq. ft., the T5H would produce almost twice that amount of lumens.

Fixtures come in all kinds of configurations and sizes, so you can certainly find a fixture, particularly a fluorescent fixture, to fit that space. The "standard" T12 bulb is 1 1/2" wide, the T8 bulbs are 1.0" wide, and the T5 or T5H are around 1/2" wide. Thus, you can have six or eight of T5H bulbs in the same size fixture that would only hold four T8 bulbs.

I guess I am confused by the numbers (worse than the ones on the fertilizer bags). What are the numbers (watts, lumens, etc) that I would be looking for. For cattleyas, Dendrobium etc. not vandas (which autocorrect just changed to vandals), not phals. I have 2 little masdevallias which I wanted to put into the vivarium at work anyway, if I go back there.

Do all of the, fit into the same sockets (whatever they are called?). All of the ones I mentioned are from a place called Orchid Light in Burlington, VT.

All very complicated! My DH would say, why don't we just move to Florida or the Caribbean and we would not have all these problems!

Or get a glass ceiling.......?

A glass ceiling would work, but if it were me putting it in, with my luck, a piece of space debris would come crashing through.

Lore, all these fixtures simply plug into a 120V outlet. I have timers on all my lights, but the new T5H fixtures have on-off switches on the fixtures, so you can easily turn them on or off.

Lumens are simply a way to describe "brightness". The more lumens there are, the brighter the light. Sunlight will have variable lumens throughout the day, with the peak lumens being when the sun is directly overhead (this is far more complicated when considering the angle of the sun, but let's just keep this description simple).

Kelvin (K) shows the light spectrum or "hue" of the light. At the low and high ends you would have infrared (less than 2500K) and ultraviolet (more than 6500K [we'll eliminate x-ray to keep it simple]). Both infrared and ultraviolet are at the invisible ends, so the visible spectrums would be between those extremes. A 2500 K bulb would be considered a "warm" color (more yellow) and then as you increase the K, you would get into what's called "daylight" (5000K) and "full spectrum" (6000K). These terms are not scientific terms, just what manufacturers use. Go by the K number, not the term. Generally speaking, the full spectrum area is needed for plant growth and the warm spectrum for flowering. Again, this is very simplified. You wouldn't want to use bulbs that emit infrared, because the heat produced would burn the plants. Our sunburns are caused by infrared. You also would not want to use bulbs that emit (much) ultraviolet, because the UV can cause tissue changes in the plants and damage our eyes and skin. UV is what causes our skin cancer.

OK, wattage. Again, to keep it as simple as possible, the higher the wattage of a bulb the higher the lumens and with the typical incandescent bulb, the higher the wattage, the higher the K. Also the higher the wattage, the more electricity is used. That's one reason that fluorescent bulbs are less expensive to burn than incandescent bulbs. A fluorescent bulb might be 40W but produce the same lumens as a 200W incandescent bulb. More lumens but less wattage equals less electric bill to burn a fluorescent bulb.

Oh, I wish I knew more than I do so that I could describe all this in better terms. I am sorry, Lore. I am a dentist (past-tense) and not an electrical engineer. I welcome anyone to jump right in and make this more clear.

Here's something that may be helpful, on the Andy's Orchids site they list how much light each species is recommended to have for best blooming (I assume). http://www.andysorchids.com/pi...

Light is listed in footcandles, not lumens though so I guess we'd have to convert. http://www.ehow.com/how_594675...

Ken and Elaine,
Thank you. Ken, I am so happy you didn't get any more technical, I find it difficult enough!, you may b a dentist but I am only a brain damaged neurologist who never took physics in college! Oh well, we're lovable anyway. I will have to go back to the Orchid Light site and check on the numbers or, if they don't provide the information, maybe look for another vendor.

Here's something odd. I was speaking with a friend today and she said that she had heard that a love of orchids was associated with pain and sadness, from a need for beauty to balance out the pain. I can't say I've ever heard that before.

Gosh, Lore, I must have endured a lot of pain in my life. Well, being a dentist............................

I didnt know you were a dentist.. I still have my wisdom teeth in a dawer in my room. people gawk when they see um, lol.


How much lumens would a 4 foot long by 2 foot wide sunleaves t5, IV put out I have a moth orchid hybrid I got from someone as a gift.

I don't know what the lumen output is. Find out the K and then Google that specific bulb. If there are four bulbs in the fixture, just multiply the lumen by 4. You can find the bulb type (be sure it is T5) and the K on the bulb itself. Just guessing though, that fixture with four T5 bulbs will put out a good deal of light and would be adequate for several orchids you have beneath it. Just be sure to position the fixture within a few inches of the top of your orchid(s). The T5H or sometimes labeled T5HO would produce almost twice the light as the regular T5 bulb.

Oh, I am a retired dentist.

Lorli....wow. That's very heavy. My family has told me I inherited my botany obsession from my grandmother, who turned every bare piece of dirt she found into an oasis, but now I'm starting to wonder about my love for orchids, tropical beauties and bizarre succulents...!

I don't use lighting at all, and now I'm worried? Do you use florescents during the winter when the days are short?

I wouldn't worry, Kate. We have plenty of light here for our orchids. Aside from our clean air and intense sun we average a lot fewer cloudy days through the winter than people up north (Lorli is up in NY) because we are generally south of the weather fronts.

Our days here in FL are at least 2 hours longer even in winter than days up north. Of course we pay on the other end, they have longer days in summer than we do.

Yes, but most summer days we are happy to see the sun set and give us a little respite! Although, I haven't met a high temperature I didn't like.

Good to know. I am new to all of this and I fret needlessly on occasion!

My greenhouse has a glass ceiling and I don't use any additional lighting here in NJ!

There is a polycarbonate ceiling on the OC with 50 percent aluminet over the top. No extra light or heat required in my local. The key is air movement. Six foot high sliding windows open to a nice breeze off of the lake and are supplemented by electric fans.

Jim