Need a little advice for growing under lights

[naturepath]

Hello.

In my shelf, where I have my orchidarium, I also have a second - lower - level (under the terrarium), where I have a little light fixture (four t5 bulbs 24w).

The light level beyond this fixture on a 65 x 45 cm shelf tray is from 4500 lux (when using only two bulbs) to 8000-13000 lux (when using all four) - depending on the distance and position on the shelf.
The bulbs hang 45cm beyond the shelf.

Some masdas, I placed there to test this, got burned leaf tops, but some buds (leafs were 25 cm from the bulbs).

I now want to decide wether to use this culture place for little paphis or for angraecoid orchids.

Temperature in the room is from 20 Grad Celcius (68 Fahrenheit) to 28 Grad Celcius (82 Fahrenheit) in summer day - depending on outside temps to 12 Grad Celcius (53 Fahrenheit) to 17 Grad Celcius (62 Fahrenheit) in winter night.

Could you please give me some advice, which genera I should choose?

Regards
Frank, germany

[WhiteRabbit]

[jeremyinsf]

My experience is that plants need to be further away from bulbs than some others have said. I've also removed some bulbs from my 4-light fixtures, taking them down to two. However, I use 54w T5-HO blubs, which are different than yours.

Some of my Masdie's do well under the lights, but some do not. It's the thicker leaf ones that do well, not the others. I think they really want to be outside.

Btw, most of my plants are Paphs.

[naturepath]

Hi.
Thanks for your reply.
Which light parameters do you have (intensity, lux or footcandles) at the plants?
Regards
Frank

[jeremyinsf]

5000-10000 depending. But I just use the phone as a light meter, and they are not known for being accurate. I just play it by ear. Also there is a big difference between the center of the shelf, directly under the bulbs, and further out around the edges. It's part of why I removed bulbs - to create more room with less light. What I've been reading lately that seems to fit is more like 18", and in some cases up to 24", away from the kinds of bulbs I have.

[naturepath]

Hi.
Thanks.
You mean footcandles or lux?
You use the phone as light meter?! How?
Regards
Frank

[jeremyinsf]

lux.

For the light meter, check out this thread:

Light meter phone app

[naturepath]

Thank you.

Nice hint. Will try it.

[Gthumbz89]

I would try out a cheapo 20 dollar light meter from a hydroponic store to measure your levels. These meters will give you a more relatable reading in footcandles. Usually low light phals need 1000 footcandles and things like cattleyas need 2,000 footcandles and up to bloom properly. Just my . Maybe someone else can give you info on how to interpret lux readings instead.

[jeremyinsf]

1 lux =
0.0929030436 footcandles



So about 10764 lux = 1000 footcandles