Question
Hi Wayne King,

I'm thinking to set up artificial light for Phalenopsis as
there is very poor light available indoor even at
windowsill.

I bought 75 watt warm white & 100 watt day light bulb. Both
are compact type as there are some problems with normal 4
feet length tube.

I'm going to grow my Phalaenopsis in the area of
1 ft x 3 ft.

My questions are:
1) Will these two compact bulbs ( I have two lamps which are
1 ft high for these bulbs) provide enough light for
Phalaenopsis.

2) How many foot candles will I get from these bulbs?

3) Since , the area has poor ventilation also. I want to use
a small fan.  Do I need to leave it on for 24 hr?

Your quick response is much appreciated.

Nwe Lay


Answer
If you have just two or three plants for this amount of space you may be okay with the two compact bulbs.  I assume the compact bulbs are the energy saving type and, therefore, generate very little heat.  If so, you would best place the plants as close to the bulbs as possible. Florescent light fixtures contain reflectors which focus the light more, whereas, your compact bulbs may not do that.  Hence, to avoid losing a lot of the light intensity, you need to position them so the plants get the bulk of the light energy.  My best guess is that if these bulbs are within 6 inches of the leaves, you should be providing 500-1000 FC.  It would be best to use a timer and set it to provide a day length at least two hours longer than normal day length.  We need to look at light requirements not only in terms of FC but also in terms of duration (ie total light exposure).  

Function of a fan is two-fold:  cooling and evaporative.  If the temperature in your growing area is regularly 80 degrees or above, you probably should run your fan 24 hours.  If the temperature is usually cooler than that, you could turn on the fan each morning when you water to promote evaporation from any leaf surfaces that might have gotten wet. A third option is to connect the fan to the same timer you use for the lights.