Need source for 5000K T5 Biax light bulbs
 

I'm planning to purchase a 24" high output T5 Biax light from High Tech Garden Supply. The light comes with two 6400K daylight bulbs which are more in the blue spectrum. The only other T5 Biax bulb that they offer is a 3000K bloom bulb which is in the red spectrum. Can anyone recommend a source for 5000K T5 Biax light bulbs? If not, if I use one 6400K and one 3000K bulb in the light fixture would it approximate of what a 5000K bulb would provide? Thanks for your help.

I have often recommended this company .: Sunlight Supply - horticulture and aquarium lighting systems :. Website and I know others have purchased the 24" 4 lamp fixture. Check the web site and see if there is a vendor near you. I use the 4 tube 48" fixture ans swear by it (not at it :biggrin: ) it's a great fixture.

Hi! Upon recommendation of Ross, I purchased a T5 light as well, I don't think I used the same company but I purchased the New Wave T5 light and mixed the bulbs and used both the 3000K and the 6500k (upon recommendation of Ross). I love the lights and would love to buy more when money allows!

Here is a link to the website I purchased from, I had them shipped and I had no problems. I purchased the 2ft 8 bulb light instead of purchasing two 4 bulb lights and the bulbs were included!

New Wave T5 Light, New Wave Florescent Grow Light, New Wave Fluorescent Growing Light, New Wave High Output T5 Lighting, Low Profile New Wave Grow Lights

I looked at the 3000K and 6500K bulbs that you mentioned in your inquiry. Unfortunately they do not show the actual output spectrum of the bulbs. However, red and blue are exactly what you need, but it needs to be in the correct wave length range (approx 400 nm and approx 680 nm).

Actually 6500K is not as blue as you think. It's about like a cloudy day. It might not be blue enough that's why you need to see the actual output data.

I'm curious as to why you want 5000K. It's a little more yellow than daylight but not much. It is unlikely to be the best for plant
performance. I'm getting kind of interested in where this plant lighting information originated because there seems to be some confusion on the subject.

How about some discussion as to what you and others think is the correct lighting. I used to grow under lights but now grow in a greenhouse so I have no real current data of my own. I'd be interested in what you might have to share.

I'm leaving this question to be answered by Ross and others as I am no expert!

Here are a few resources for those questioning the input of a photographer :biggrin:

Guide to colour temperature
An explination of Kelvin Temperature and where our 5500K Life-Lite lamps measure on the Kelvin Temperature scale
Full Spectrum and Light Bulbs with a Color Temperature of 5000K or Higher.
Light Box Full Spectrum Controversy : Apollo Health
Natural Lighting
Yale Appliance + Lighting: Kelvin temperature of Lighting

Do I need to go on? There are substantial resources indicating sunlight at noon at the equator as 5000-5500 K. The assumption is we can provide only one K reference, unlike the sun that goes from low K (warm) in morning to high K (cool) in afternoon or shade then back to warm (low K) in evening. Thus the push by landscape photogs for the "best light" of either early morning or late afternoon. They are after the warm glow of the light. Since we growers (under tubes) can only provide one spectrum, what shall it be? My contention (and lots of others) is the best balance of noon day sun at equator or thus 5000-5500K. That's where the idea is from. Like it or not. ;)

c

I'm not claiming to know much about the science about artificial lighting and natural lighting, but upon trying to do some research to answer your original question, I found that many books that talk about artificial lighting FOR orchids refer to aiming for 5000k or a mixture of bulbs to achieve as close as possible to 5000k, so perhaps since all their information seems to be incorrect, you should write/publish a book and provide us all the correct information so that we won't be mislead because there is plenty of misleading out in the world today, and please make sure you put it in simple enough terms that us regular people can understand it! We do have a blog section that would be perfect for you to start on! Also, can you advise us as to where we can purchase lights that provide a wave length range of 380 and 689 nanometers? I have a hard enough time just finding the Kelvin temperature on bulbs. And if aiming for 5000k is doing nothing for our orchids, I would love to see the results of using the proper lighting because the results I have seen so far have been wonderful.

Here is a link I found on Ray's website that might help us understand better what goodgollymissmolly was trying to explain to us:

Light

Becca, I removed my post above as a result of you and Ross wanting to argue with scientific facts. I have no desire to upset either of you with facts. Note for the record that I never directed any comments towards either of you, but you chose to direct your comments at me.

Look at the spectral graph on Ray's site that you referenced. It says exactly what I said. That is, plants have very narrow spectral needs. If you fail to satisfy those needs, the plants will suffer or even die because they can not initiate the photosynthesis chain of food making reactions. The absorption of a suitable photon which results in the ejection of an electron from the chlorophyll molecule is the first step in photosynthesis.

I apologize for attempting to state some facts. I did not realize that facts upset people. I thought they wanted facts. My bad!!

Goodgolymissmolly, I am sorry if I offended you, I didn't mean to get into a pissing match, it wasn't my intentions, and I understand that looking at Ray's graph is what you were trying to say, he just states it a little bit easier for us non technical/scientific people to understand, and that is why I provided his link and also stated that his link is what you were trying to explain, just a little easier to understand. I hope there is no hard feelings, I want us all to be friends! And I was really serious when I asked if you could direct us to a website that states a bulbs nm, I have never seen that before and I would think it would be something neat to try.
Again I apologize and hope there are no harsh feelings, I would never argue scientific facts, they are just sometimes hard to understand and grasp when one has never heard of it before. The more I read, the more I understand, and you are a great asset to the Orchid Board Community.