Just Changed My Lights - Orchid Board

Becca · #1 02-10-2009, 11:11 PM

I just changed my light bulbs in my Grand Cayman Orchidarium. I bought replacement bulbs (55W Single Twin Tube 4000 lumens per bulb) and purchased half (3) 3000K bulbs and half (3) 6500K bulbs. I ordered the combination of warm and cool colored bulbs because that is what I have been reading is best, and also came with my T5 light fixture. So as I was changing out the bulbs I noticed that half of the bulbs were 4100K and 3000K bulbs. What the heck? I swear I had looked at them before but I must have looked at the 3000K bulbs when I was writing down the type and model number I needed. I still got great growth and a few nice blooms from some oncidium's, dendrobium's, and a few catt's and the leaves have been a nice light green color. So now I am wondering....does the whole Kelvin thing really matter that much or have my 'chids been missing out?

Magnus A · #2 02-12-2009, 04:54 PM

Becca, It does not matter that much as long as you give sufficient light over the spectrum. The color temperature is on most lamps depending on a stronger band of wave lenght compare to the overall. If this stronger band is in the yellow you get a low temperature and if it goes against the blue you get higher.

Becca · #3 02-12-2009, 05:59 PM

But would a 3000K bulb and 4100K bulb together really give sufficient light over the spectrum?

Magnus A · #4 02-13-2009, 08:54 AM

If they are T5 they are most certainly "full spectra" bulbs! And they at least deliver light covering the hole visible spectra!

The first picture shows the relative spectral output for a 4000K T5 tube:

The second picture show the same series of T5 but the 6500Ktube

What you can clearly see is that there is significant amount of blue light in the 4000K. This also holds for a 3000K tube (not shown)

nhman · #5 02-19-2009, 01:13 AM

NICE VISUAL Magnus!!
Sticky???
Well done.

Becca · #6 02-19-2009, 11:17 AM

Magnus, your pictures do really help to understand what you are saying! Thank you so much!

On another note, it has been a week since I put my new bulbs in and I can't believe how much stronger they are! They were about a year and a half old. Some of my cattleya leaves are showing some redish-purplish coloring in the leaves. I am almost considering dropping the shelf down to it's next level, about 5 or 6 inches inches so I don't burn anything!