Claude,

The larger, higher-output fixture is probably the way to go. Fluorescents
are low on the lumens output, so there's no fear of too much light -
besides, you can always increase the distance to the plant...

As to the bulbs themselves, are you sure about your descriptions? Daylight
and cool white are usually not synonymous.

I don't have the Sylvania specs handy, but in 40W, 48" T12 GE bulbs:

Cool White 2575 mean lumens, 4100°K color temp, color rendition index 60
Daylight 2775, 6500, 75
Chroma 50 1870, 5000, 90
Warm 2910, 3000, 70

Higher lumens = stronger light, can grow higher-light-demanding plants
easier
Higher color temp = generally closer to natural light
Higher CRI = spectrum closer to that of natural sunlight (resulting in more
natural-looking colors)

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

.. . . . . . . . . . .
"Claude" wrote in message
news
Hello everyone!

I`m in a process of changing my lighting system. I have a question:

What is the best:

1 48 inches fixture with two tubes

- 2 tube 40 watts Sylvania DayLight ( cool white ) OR
- 2 tube 40 watts Sylvania warm light ( Grow-Lux )

OR
- 1 tube of each

Is two tube of 40 watts too much? I also saw some 24 inches fixture with
20
watts tube?

What is the best knowing I`m growing mostly Phal, Paph and Onc.

Thanks

Claude