Distance between light fixture and plants .....

[camille1585]

I remember Ross recommending one (back when he was active on OB). I'll try to look it up, or I'll ask him about it.

[camille1585]

Found it, this is what he uses: Buy Light Meters Lux & Foot Candle l 5 Year Warranty l Sper Scientific This one does Lux and Fc, but there's an Fc only one that costs less.

Have a look at this thread too, there are a few recommendations. Light Meters

Or just create your own thread here to get some advice about what to buy.

[NeoNJ]

Ok, I figured it out. The Light Meter was not calibrated correctly. The "needle" was not set to "0". I re-calibrated the Light Meter and tried this again ....
Now I get a reading of 3000fc of light --- far less than the 5000fc of light that I initially thought the plants were receiving.

The needle actually fluctuates between 2500-3000fc of light with my current lighting system.

I think this is a more realistic figure for the bulbs/distance I have.

[camille1585]

Sounds like much better readings. This is at 18" from the lights? Or right under?

[NeoNJ]

Actually, the CFL lamp fixtures are a good 22-30" above the actual light meter, which is on the windowsill.

The 3-lamp fixtures are at different heights from one another. The Center fixture is lower than the two on the sides. This is to accomodate the mounted orchids on the inside walls.

However, the mounted orchids are much closer to the lights ---- > hence, the "yellowing" of the orchids, so I've had to turn the reflector to avoid a direct hit at 12" away, since the mounted orchids are all Angraecum and Aerangis orchids.

[Brotherly Monkey]

I have a Sper Scientific 840020

[Brotherly Monkey]

you'll be surprised at all the variations you get in lighting intensity, from one foot print. I suggest measuring around the area, and moving the plants to the lower end of their need, and then working them into higher light.

You'd be really surprised the difference the sustained intensity makes, that you get under artificial sources

[NeoNJ]

Camille, I forgot to tell you --- this morning, with the sun coming in the window, and the 3-CFL's turned on, the Light meter did register 5000fc of light. So, the sunlight + the supplemental lighting will provide this level of lighting. When the sun moves, the CFL's will provide 2500-3000fc of light.