Lumens for my new phalaenopsis

[hypostatic]

Originally Posted by Ray

Like this.

Ah OK, so the general formula is: for constant artificial lighting, use half as much as recommended when growing under sunlight. So if 2000 FC is recommended for greenhouses, use about 1000 FC.

[ghuylar]

Generally, the more light the better! Next to a window will also allow it to get the cold snap it needs in the winter to form a new spike.

[Ray]

Originally Posted by ghuylar

Generally, the more light the better!

Not for all plants. Take phals, for example. They're deep-shade plants in nature., so more light can translate to fewer, shorter-lived blooms.

When I moved to "better" conditions by building a greenhouse and moving my plants from indoors, I was confused as to why my phals bloomed less than they had. Now that I'm (decades later) back to windowsill growing - north-facing, no less - after about a year of adjustment, my phals are becoming more floriferous again.

The best-blooming phals I've ever seen were in a very hot, very humid greenhouse that was SO coated with algae, absolutely no sunlight got in.[COLOR="Silver"]

A foot-candle is a lumen per square foot. A lux is a lumen per square meter. Imperial and metric versions of the same measure.

Lumens are used to specify the total light output from a source. Both foot-candles and lux tell you how much is striking an area of surface. Certainly, lumens can be used to determine the intensity at the plant, but that is not what it is intended for.

What is actually most important is the volume of light that reaches the plant over the course of a day, known as the Daily Light Integral (DLI), and that is measured in micromoles of photons.

[camille1585]

Originally Posted by Ray

Not for all plants. Take phals, for example. They're deep-shade plants in nature., so more light can translate to fewer, shorter-lived blooms.

When I moved to "better" conditions by building a greenhouse and moving my plants from indoors, I was confused as to why my phals bloomed less than they had. Now that I'm (decades later) back to windowsill growing - north-facing, no less - after about a year of adjustment, my phals are becoming more floriferous again.

The best-blooming phals I've ever seen were in a very hot, very humid greenhouse that was SO coated with algae, absolutely no sunlight got in.

After years of wondering why my Phals produce smaller spikes, I think I now know why, thanks to you! Before moving to my current appartment in 2014, I kept all my Phals on the only windowsill I had, facing north-east and I had tons of blooms per spike. I moved and the orchids went to a south facing window, with the Phals getting bright indirect light with some direct sun late in the day. The Phals weren't doing well, but I put it down to the long period of neglect when I was finishing my PhD. Several years later, even with good care they never flowered as great as they did pre-2014.... I think I'm going to move them to the lowest shelves and add a fairly thick sheer curtain to the lower half of the window.

[SouthPark]

Originally Posted by camille1585

I think I'm going to move them to the lowest shelves and add a fairly thick sheer curtain to the lower half of the window.

It is quite interesting ----- like 'slow and steady' (growing in less light) versus growing at a faster rate. Like ---- slow and big ........ versus .... fast and small.

Flower colour or colour effect probably also depends on light intensity too. Whether grown in low light or high light, there are probably always exceptions. Such as ---- depends on what sort of phal we're talking about.

[Roberta]

Originally Posted by SouthPark

It is quite interesting ----- like 'slow and steady' (growing in less light) versus growing at a faster rate. Like ---- slow and big ........ versus .... fast and small.

With regard to Phalaenopsis, consider the habitat of the majority species that are in the ancestry of most hybrids - they grow in warm, humid locations near the equator (substantially equal days and nights all year) on trees in heavy forest - so fairly shady, around 12 hours of soft daylight every day. Growing on trees, they get rained on, then dry out when the rain stops, but humidity is high all the time. The closer we can come to those conditions of light, warmth, humidity, and a wet-dry cycle, the happier our Phals will be.

[SaraJean]

Originally Posted by Ray

Not for all plants. Take phals, for example. They're deep-shade plants in nature., so more light can translate to fewer, shorter-lived blooms.
[COLOR="Silver"]

well that answers a question I didn’t even know I had

I’m not really a Phal grower but I do have a few. The little NOID gifts from friends always bloomed extremely well when they were tucked in a dark corner of the courtyard under the balcony. Minimal light over in that spot. I moved them to the bench in the shade house a couple of years ago so I could take care of them better. They grew well but I’ve had crappy blooms since. Now I know! Back to the corner they go

[SouthPark]

Here's a nice link about lux and lumens.

Click Here.

For orchids, the lux quantity is expected to be the more relevant quantity of interest here. Or more immediately useful for this situation.

[SouthPark]

I forgot to mention that the details of the link are quite general - but helps to get the point across.

I think a lot of online information about the topic of 'lux' misses out certain important details, such as the assumed kind of lighting (eg. uniform light flux distribution), and distance of light receiving surface (ie. its distance from the light source), and shape of surface, and surface area of surface.

But that's ok - since we know that leaving out important details is the life story of lots of information sources.

[wisdomseeker]

I hesitated replying to the OP's original post because I know the subject of lighting can become very complicated, and often produces a lot of contention. It was because of the OP's second post, I decided to reply.

I'm sure many people follow the KISS principle... they really don't care about technical jargon or how one comes to the conclusion of producing an answer... they just want a simple answer to their question.

I would venture a guess that many go to a good website for cultural information about an orchid (e.g., Andy's orchids). You look up the plant that interests you and find a recommendation for light. Example: shade; 500-1500 footcandles (indirect low light, slight shadowing).

More than likely, one starts thinking to themselves: how do I know if my light is within the 500-1500 footcandle range? You really don't know unless you can figure out how to measure that light. For me, having an inexpensive lux meter helps to do just that. It's not perfect (and surely does not compare to using a good Par meter), but it definitely gives a good 'guesstimate' to help figure out if my light is within the range recommended by another.

817 x 10 = 8170 lux, which converts to 759 footcandles. I think most orchid growers realize it's not just a matter of light, it's more of: "am I providing a balanced growing environment for my plant" (knowing that light/temperature/water/food/air makes up the team for a balanced growing environment).