Distance between light fixture and plants .....

[NeoNJ]

The Light Meter I have is an OMNI Light Meter. And it registers a consistent 5000fc (The light meter is on the windowsill, and the light fixtures are 18-30" above the light meter).

I have 3 clamp on fixtures - (1) with a 32-watt spiral CFL/6500k, (1) with a 26-watt spiral CFL/6500k, and (1) with a 40-watt spiral CFL/2700k.

The mounted orchids on the side walls are 12" from the light source.

Since the light meter is below the mounted orchids, I will assume the mounted orchids are receiving light levels that are higher than 5000fc. So I think I need to raise the light fixtures, lower the mounted orchids, or change the intensity of the CFL's.

Any thoughts ?

[Brotherly Monkey]

1) I thought you were using a 100 w spiral bulb?

2) what type of reading do you normally get with the lights off, and with the lights on, without outside interference?

PS is that true watts or equivalent?

[NeoNJ]

I thought I had 100w bulbs too, until I unscrewed them and looked at them. I don't know why I thought I had 100w bulbs! I definitely don't !

1-bulb is a 32-watt/6500k bulb, and 1-bulb is a 26-watt/6500k, plus, I also use a 40watt/2700k bulb.

The 5000fc reading is with the LIGHTS ON, and NO sunlight thru the window.

[Brotherly Monkey]

how familiar are you with the meter? Because I don't think you're likely to get 5000fc from a 26 watt bulb, at a 3 foot distance

[camille1585]

I'm thinking like Brotherly Monkey. If it really was 100W bubls, then 5000fc would be an expected number. But for 26 to 40W bulbs, that seems almost unrealistically high. Are you sure that the meter isn't giving you Lux instead of Fc?

[Brotherly Monkey]

YouTube - Jacques Brel - "Amsterdam" live

[NeoNJ]

Could be. Can't really say that I'm "familiar" with the light meter. It's a light meter. I've used it for about 6-years now. Perhaps I should invest in a new light meter and try again ....

Whatever the fc's of light being offered to my orchids, many of them are turning Yellow ...... with that being said, it speaks of there certainly being sufficient light being provided somewhere in my growing area .....

It just may be the "distance" needs to be fine-tuned.
But I'll invest in a new Light meter - although many feel they are highly unreliable, no matter what meter you invest in.

[camille1585]

Light meters are not 100% accurate, but they're close. Some are better than others though. What's the make/model you have? Maybe we can try to figure out how yours is supposed to work.

[Brotherly Monkey]

Originally Posted by camille1585

Light meters are not 100% accurate, but they're close. Some are better than others though. What's the make/model you have? Maybe we can try to figure out how yours is supposed to work.

I agree with Camille. Let's see if we can figure out if it's something easily resolved, before we worry about anything more complex

[NeoNJ]

You guys are wonderful for being so helpful and concerned. And I thank you for that ...
problem is, the Light Meter I use was given to me by a Friend - the Light meter dates back to 1974. It is an OMNI Products Light Meter. No Make, No Model Number.
Duh. So, I think I now need to invest in a new Light Meter that is a bit more current. This one is quite elementary - it is 2" x 2" and has a needle that moves.
It's calibrated with numbers, the numbers tell you how many "fc" of light. Quite simple. But probably not real trustworthy or accurate. Back to square one..

Now I just need to Breeeeeeeze thru the thousands of Light Meters available online and see what would be worth investing in and what I can afford ..........



In the interim, I'm going to tone-down the lights.....
I keep them on 12-16 hours per day, so maybe my plants (hopefully) are getting 2000-3000 fc of light (?)