Conflicting PPFD/LUX recommendations

[guccisimo85]

Hello!


I have been perusing a few different sources on light requirements for high light orchids (e.g vandas, cattleyas). I seem to be seeing conflicting information. A few resources suggest around 50k lux / 4500 ftc (which seems correct to me). I know they need lots of light. There is this a popular guideline however on a few threads which seems to be in conflict (see below). My understanding is that 50k lux will be around 1000 PPFD, so 200-300 seems extremely low. Can anyone clarify? Not sure if it has something to do with the units being m2 or ft2? Seems like maybe there is some inconsistency in units and resources are off by a factor of 10?

Thanks!

Light Targets for Orchids

20 umol/ft2 (~65 umol/m2s PPFD) – for low-light orchids (Phals, Paphs, Jewel Orchids)
30-40 umol/ft2 (~131 umol/m2s PPFD) – for moderate-light orchids (Oncid, Phrags, Epidens, Dends etc)
50-100 umol/ft2 (~200-328 umol/m2s PPFD) – for high-light orchids (Cattleya, Vandas)
**Converting feet to meters: 1m = 3.28ft