Correct light levels for orchids

[EarlV]

I have a meter for the weekend and I am measuring the light of my set up it varies quite a bit by location from 200 ppfd to 1000 ppfd.

Masdevallias are near the lower light areas and cattleyas are in the higher light areas with paph/phrags/max/dendrochilium/onc in between.

It is a mix of fluorescent, led fluorescent, and led panels that are blue/red with a few uv/ir/green mixed in.

Blooming is my problem but light levels seem high enough...right?

What is correct levels for various orchids?

Attached are an example minicat, dendrochilum, and masdevallia.

[Ray]

Full, noontime sunlight is 2000 micro moles/sec/square meter, so your brightest lights would be great for terete leaved vandas, but too great for most other orchids. (When under artificial lighting at a constant intensity, the light level should be about half of what they’d get at noon in natural light.)

A crude conversion for artificial lighting is to take the AOS culture guides - light recommendations are given in foot-candles - and divide them by 10 to get the ppf levels.

[EarlV]

Thank you, so I am nuking my Masdevallias at 500 ppfd since 500 fc is really 50 ppfd.

That also explains why my Dendrchilums that moved from an east window to the grow tent after they bloomed had much smaller leaves. They are under 1000 ppfd or 10000 fc.