Indoor Light Levels for 12 Hours

[kaede]

I was reading this article which is the only one I can find that is specific about light requirements indoors.

Check out the list she has under "Measuring Light" :

Indoor and Supplemental Lighting for Orchids


What do you think of the indoor light levels she recommends for 12 hours ?

I'd be happy to use those levels as a guide, if it's correct. That means I have way too much light at the moment and need to adjust (which is easier to do than not having enough light).

[katrina]

Something isn't right about her recommendations. It looks like her conversion from Lux to Footcandles is off. I don't know anything about lux...I only use footcandles when I measure.

Her quoted recommendations:
Low light requirements
800-2100 lux (74-195 foot candles)

Moderate light requirements
2100-5400 lux (195-501 foot candles)

High light requirements
5400-10,800 lux (501-1003 foot candles)

Very high light requirements
more than 10,800 lux (more than 1003 foot candles)
End of Quoted.

Even her listed very high light wouldn't be sufficient FCs to bloom some phals.

I've seen various guides to footcandle recommendations...I don't know that there are any hard and fast rules...just ranges of recommended levels. Here are a couple of links w/some useful info...I probably more closely follow the first link but the 2nd one is very good too.

Orchid light | Everything Orchids

Carsten's Orchid-Depot and Orchid Shop

[kaede]

Her conversion from Lux to FC is correct ...

Thanks for those links. But like maybe 99% of articles about light, they only mention the maximum range for a particular orchid - i.e. 1200 to 1500 FC for phals. Even in indoor light articles ...

My phals outside in my balcony get about 2 - 3 hours morning sun. And morning sun is like lux 20,000 up (1800 fc up).

In the article, she is talking about artificial light for 12 hours, and not just 2 to 3 hours.

In First Rays website, Ray did talk about it briefly :

Light Level Recommendations - First Rays Orchids

I think Ray recommended to be half if I understood it (full according to all those other articles means overdoing it). Like for 1500 fc, use 750 fc if long duration (like 12 hours)

I am just curious, and I guess must ask her how she derived her figures.

I do have some phals under her recommendation for low, moderate, high light requirements, depending on species, and all are growing and blooming well.

[Gthumbz89]

I always tend to err on the side of giving too much light than too little. That being said on the plants that I don't care for as much as orchids I have found that the high light plants can bloom well with long photoperiods at half the quoted maximum strength as growing in daylight. The plant I am referring to is a sinningia speciosa by the way.

[kaede]

Thanks, Gthumbz. Mine is the opposite. With the phals I have, I think they are sensitive to light, so I prefer not to go over. To quote Ray :

"Also keep in mind that plants can be fairly adaptable about light levels, and that “more” is not necessarily “better”. I have seen vandaceous plants adapt quite well to the lower light levels of windowsill growing, while phalaenopsis grown in too much light simply refuse to bloom at all!"

I once made the mistake of bringing in a new phal and not acclimatizing it. I immediately put it under moderate light, left it, and found within the week that it's leaves were getting yellow spots fast. I guess it was grown in low light at the nursery, so I moved it to lower light and it has recovered.