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Tip for measuring amount of light

Posted by bedtime none (My Page) on
Sun, Apr 21, 13 at 16:39

If you have an Android device you can download an app that will measure lux and lumens. I imagine Ipad would have the same thing but I cannot promise. My android will measure anything from 0 lux all the way to over 110,000 lux and it 'seems' quite accurate though I have nothing to compare to.

I've been walking around the house measuring in corners, and here and there, to get a better idea of how much light is actually getting there and it's a big help. I was always curious what kinda light gets behind the balconies shadow outside, and now I know. Its about 4000-8000 lux, which is fine for a lot of low light tropicals. I wouldn't have any idea without this reading. Its just too much of a guess to me. One corner I thought might be too dim for a plant was infact bright enough (2500 - 3500 lux in afternoon sun), so I put my Monstra (pic below. measured at 2430 lux at time of picture) there and it seems happy. Another corner I thought would be adequate was not nearly bright enough (350 - 450 lux). It's a difference of almost 10x but by eye I couldn't tell. This comes in so handy!

Just search in your app store for 'lux' or 'lumens' and you'll find a few to play around with.

Hope this helps!

This post was edited by bedtime on Sun, Apr 21, 13 at 16:40

Follow-Up Postings:

RE: Tip for measuring amount of light

For those in the states, where most measurements is listed in foot foot candle is equal to less than eleven lux.

RE: Tip for measuring amount of light


Thanx for that.

I wanted to add what lux levels equate to. The info below is from wikipedia (

Light requirements

The meaning of Low-Medium-High depends on the context. For example, in orchid literature 1,500 foot-candle is referred to as Low Light.

Most plants will survive illuminance 10 times lower than listed below but will not grow as well or bloom.

Low (500 - 2,500 lux; 50 - 250 foot-candles)
- North window at 40o latitude, 3 - 10 ft from fluorescent lights

Medium (2,500 - 10,000 lux; 250 - 1,000 foot-candles)
- East/West window at 40o latitude, filtered daylight, 1 - 3 ft from fluorescent lights, 5 - 10 ft from a 400W metal halide light bulb

High (10,000 - 20,000 lux; 1,000 - 2,000 foot-candles)
- Full Daylight (10,000 - 25,000 lux), South window at 40o latitude, 2 - 5 ft from a 400W metal halide light bulb

Very High (20,000 - 50,000 lux; 2,000 - 5,000 foot-candles)
- Direct Sun (32,000 - 130,000 lux), 1 - 2 ft from a 400W metal halide light bulb

RE: Tip for measuring amount of light

Well that's cool. Much more scientific than a solar-powered dancing flower. LOL!

RE: Tip for measuring amount of light

Bedtime, thank YOU! We all could benefit from a better understanding about the effects of light on our plants.

Purple, lol! Surely there's a way to measure the wiggles of the solar flowers to actual light intensity. They are adorable, I always smile when I see one.

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