2013 Archived Messages

Click on the week you require.
To return to the main Archive index, click the button at the bottom of the page.
Links to all the Photos and other images accompanying the list messages can be found on the Images page.

January 1-7 8-14 15-21 22-31 February 1-7 8-14 15-21 22-28
March 1-7 8-14 15-21 22-31 April 1-7 8-14 15-21 22-30
May 1-7 8-14 15-21 22-31 June 1-7 8-14 15-21 22-30
July 1-7 8-14 15-21 22-31 August 1-7 8-14 15-21 22-31
September 1-7 8-14 15-21 22-30 October 1-7 8-14 15-21 22-31
November 1-7 8-14 15-21 22-30 December 1-7 8-14 15-21 22-31

1—7 October

From: Geoff
To: Orchid Talk List
Subject: LED lighting...
Date: Fri, 04 Oct 2013 20:45

Very technical, but maybe someone has some answers ?

LED lights. They are the latest thing, and have the remarkable
advantages of low electricity usage and very long life.

I became aware of them when I saw my new car and checked things out.
Then I bought three for my bathroom (lamps, not cars ! ) − a brighter
light for shaving by replacing three 20 watt halogen bulbs ( life
usually less than 1 year) with three 1.8 watt LEDs − life , said to be
good for 30,000 hours of usage .
I reckon my bathroom lights are on for an hour a day, total. They
should be good for 85 years or so . I am not Methusalah...but this
eases worries about getting value from equipment before it wears out.

So that started me thinking about the lamps in my greenhouse, especially
since LEDs are available in a range of specific colours for
horticultural use. One lamp assembly has 1% emitting infra-red only,
another percentage emitting at the red end of the spectrum ( all this
for vegetative growth, and another percentage at the blue end, for
flower production. Fantastic − especially if the running cost can be
10% of what it is now .
Then the problems start. With the conventional metal ballast sun lamps (
blue, red , or mixed spectrum − all of which look white to the naked
eye, but warm white, cool white, etc. the lamp output is quoted in
lumens ; 1 lumen 3D 1 foot candle 3D 10.74 Lux . And I know what lux I
want on my leaves, I have measured it with a lux-meter on orchids in the

One dealer said that frankly, you just have to experiment a bit. So I
bought a couple of cheap 1 ft square mixed colours 93growlight94
panels. But after doing some experiments, I reckon my Lux meter is
useless for determining the height above the plants to locate them, and
also making guesses about how many lamps I need for a specific bench
area ( they don't seem to use lenses or reflectors btw ).

LEDs are not rated in Lumens. Instead they use quite unfamiliar units
represented by acronyms such as PAR. One trail I followed up ended with
an equivalence quote in mols − molecular weights...another dealer said
he could give me umol figures, and when I pressed , he was clearly
trying ( successfully) to blind me with science , but I gathered that he
didn91t understand it either.

So, HELP. Has anyone any experience ?



From: a.mckeown1208 e-mail
To: Orchid Talk List
Subject: Orchid Festival October 13th
Date: Mon, 07 Oct 2013 13:00


This Saturday is the Autumn Orchid festival at Writhlington School. It is
really worth a visit to see the wonderful facilities.

All the usual stuff to − displays, traders and so on. I will be there
doing our local soc display.

Here's the poster




From: Geoff Hands
To: Orchid Talk List
Subject: Re: [OrchidTalk] Orchid Festival October 13th
Date: Mon, 07 Oct 2013 17:15

I never did get to see the orchid houses at the BOC show at Writhlington − the problem was that I had to combine the visit with family at nearby Bath. So I promised myself I would go the next time I heard of an open day − and what happens ? Murphys law or something.... I shall be in Germany on Saturday!



From: Ed Deckert
To: Orchid Talk List
Subject: Re: [OrchidTalk] LED lighting...
Date: Mon, 07 Oct 2013 21:40

Hello Geoff,

I have no experience with these LED fixtures, but have seen them for sale on
ebay. Most, if not all of these fixtures seem to be made in China, and
customer reviews have not always been stellar.

You mention using these LEDs in your greenhouse, and that gives me cause for
concern from the standpoint of humidity. It would be good to know the
operational range of these fixtures as far as humidity is concerned. Many
of these fixtures are used inside of a residential house for plant
cultivation − one particularly popular use is for growing cannabis. "Pot"
houses seem to love these lamps. And the humidity levels there are likely
far less than in a greenhouse.

I would have concerns about potential electrical shock hazards, as well as
dampness degrading the electrical connections or possibly the LEDs
themselves. I recently purchased several LED bulbs to replace some
burned-out bulbs in the house, and they came with the caveat of not using
them in damp locations. Of course, your mileage (perhaps kilometerage?) may

Mind you, I am not speaking from knowledge, but am posing some hopefully
valid concerns. Please do share what you find out.



From: brian.gould83
To: Orchid Talk List
Subject: Re: [OrchidTalk] LED lighting...
Date: Mon, 07 Oct 2013 21:40

Hello Geoff
If you put on your computer www.led lighting in horticulture and look at the
"phillips"lighting section you can see the current thinking with results
from specific crops using led lighting and I think this might help you.


Archive Index
Archive Index

email.gif - 2501 bytes