best artificial lighting?

[Randy Shroy]

have a deaf friend that has built a 2x4x4 glass case for some of his orchids. We have east and west facing windows, but he wants to place some of his smaller ones this new case in the basement. They include:
cattleya trianae
cattleya hawaii
dendrobium Berry 'Oda'
ludisia discolor (the jewel orchid)
miltoniopsis
odontoglossum = wilsonara (cochioda hybrid)
zygopetalum

We are debating the best artificial light source for these prior to buying and would like your input. The light of choice between us so far is the Tek Light T5 fluorescent - 4 - 4' 3000k tubes supplying a total of 20,000 lumens (or mix 2 3000k and 2 6500k). Concern is enough light. If we went with a sodium agro we figured for a 4x2 area would need a 250 watt, but concerned about the heat generated. As we are dealing with an initial cost and future electric costs, we want to be sure we are getting the right light for their growth before finding out the hard way we didn't!

I have the mix you suggested in a 4 tube T5 setup and it would be MORE than enough light for what you want to grow. My mini catts and dends are about a foot and a half from the lamps (16 hours/daily) and grow and bloom just great. Sometimes I have to move them to the outside area as the leaves turn red at the maximum amount of light they can handle is being indicated. You've picked the right lamps but you'll want to make sure you've got good air circulation as they are a little warm...but not TOO warm.

Kanda

[ryanmor]

Hello
for what your friend has I would reccomend some compact fluorescent bulbs. They are a cheap alternative to HID lighting and are very bright. I have pruchased some from: 1000bulbs.com

When buying compact fluorescents try to stick with a color temp>6000K. Also, amke sure you buy at least two>40watts these bulbs will fit into standard fixtures and do well in one of those clip on light fixtures.

Ryan

[Randy Shroy]

appreciate the helpful suggestions from those of you that took time to reply

[Fabolusus]

I have been growing indoors with artificial light for 2 years now. I have one large setup with a 400 watt HID that converts from MH to HPS. I also have a seedling box with two 24" "cool white" flouros, supplemented with two 23 watt compact flouros. The main problem with HIDs is that you can't really put the plants as close to the light as you would want, unless you have a light mover. The flouros, especially the compacts, are more energy efficient and produce almost no heat. However, you can never generate the same amount of lumens per fixture as the HIDs. My EYE-Hortilux BLUE MH is rated at 27000 initial lumens. You would need 5 or 6 flouros to match that.

[mayres]

My personal experience with fluorescents is that I don't get that many foot candles - as reported. I don't know if more expensive ballasts can/will boost the light output of standard tubes or not? My fixtures are of the standard inexpensive types you would find at Home Depot or Lowes. Light output is only 1000 footcandles AT THE BULB and it drops off to only 700 footcandles on a few inches away. I use standard daylight broad spectrum 40W tubes including grolux tubes I've added this summer. My low light orchids - phals & paphs - are loving them and doing great - but my impression on the higher light requirement plants is that they are just holding their own and waiting until I can put them back outside in the spring? Like others have commented earlier - I've been considering the HID route for at least some of my plants but have balked at both the cost for say a 400W fixture that should light up a 5X5 square adequately and also wondered about the heat generated during the warmer months - possibly I could continue to put plants outside during the summer and then just "re-use" the heat generated to heat the house/room? Anyway - interesting thread for us who don't have greenhouses.......

[Daniel S. Barrett]

i'm using 2, 175 watt halide bulbs, they are only raising the temp a few degrees, in the grow room even with the door closed, i'm buying 8, 4' strip flours the first of dec to add to the equasion

[Daniel S. Barrett]

i've found that lux & lumines are basicly the same amount of power, but, I was raised on Footcandles! So, in researching, I've found that to convert lux/lum into footcandles you have to divide the lux/lum. by 10.76 to get footcandles. for example: 5,000 lux/lum. divided by 10.76 = 464.68 foot candles. When I started growing orchids underlights a flour tube was about 500 footcandles each, & you needed 4 of them + 2, 15 watt incandesent bulbs for the red spectrum. Now, Suddenly 5,000 lux/lum isn't so strong! I guess that why it's always been recommended that you use 4 tubes!, the term names have changed the rest is the same! you still get about 500 footcandles a tube no matter what. lux/lum or footcandles nothing has really changed. manufacturers are so sneaky!

[mayres]

Daniel - Correct me if I'm wrong (I have been working on understanding these "equations" myself) - It seems to me that four tubes doesn't really give you more intensity than one - when you are measuring close to the fluorescent tube(s). What it does, is gives you more surface area at a similar intensity. When I measure right at the surface of the tube I get 1000 footcandles. For the sake of illustration lets say that I measure 500 footcandles at a foot away (which I don't) - By adding more bulbs my footcandles remain the same at a given measuring point, but I now have more surface area at which I can get a 500 footcandle measurement. Does that seem correct to you? This at least is the fact of what my light meter seems to be telling me. On the other hand, if you are measuring the intensity of the light in a room from say 5-6+ feet away it does appear to be more of a multiplied affect? But now we are talking of footcandles in the less than 100 range.......

[Fabolusus]

You can't increase intensity by adding more bulbs...It just doesn't work that way

[mayres]

Yes, that is what I have noted.......1+1 does not equal 2

[Daniel S. Barrett]

You're right, all it gives you is more surface coverage, not intensity by adding more tubes. BUT, that wasn't my point!
my point is manufactures are telling the younger gereration that the lights now are more intense by using terms of lux/lums, when actually they are now as/or less intense as they've always been.. the only difference I see now is the light spectrums may be more attuned to what plants need. Sorry, I hope i've made what I was trying to say clearer that time..

[Daniel S. Barrett]

About HIDs, I find my catts, and other high light plants are loving it! I put up 2- 175 watt halides, & suddenly within a month everything is budding! my phals & paphs especially! I haven't needed to use my furnace in my tiny apt so far, and my day temp stays at about 75-77 degrees.
I highly recomend them.

[mayres]

Do you have a fixture in particular that you think is best? I was thinking a solitary 400W fixture - what are the advantages of the smaller wattage bulbs/fixtures instead? I'm a little cold blooded - don't think I would want my home that warm - nice that you can "re-use" so to speak your light energy though to heat up your apartment.....

[Daniel S. Barrett]

I happen to use this wattage of halide, simply because I recycled them from my salt water 55 gallon aquarium, when I was in that hobbie. But, I'm glad I did, because, spaciing them about 4' apart helps to cover a larger area, and the light is more directly above the plants, i'm lighting a 8'x6' area with nearly 300 orchids. I've just bought a 3rd halide, & i'm getting 8 - 4' flour tubes to add to the growing area also to help stimulate more growth.

[amybudorchids]

Hi-Aren't they quite expensive to run? Also do they take regular light sockets or do they need - say 220 Wiring? Don't know if I worded that correctly!!

[NievesOrchids]

I have 4 t5 fixtures running for my hibiscus. I have put my first 2 orchids under them and so far so good.

I do have a question about Kelvin numbers. Some say a mix of 3000k and 6500k bulbs. I have read that using 6500k bulbs are fine also. I just want to know does it matter


I have both 3000k and 6500k bulbs

[Brooke]

Use the 6500 bulbs - the higher the light the better. If you think the 3000 bulb will give you a needed color for blooms (I don't) then use one of those with the three higher lumen bulbs.

Brooke