Growing under lights

Leo A. Martin
Sun, 23 Feb 2014 11:50:38 PST
Tim wrote

> I don't see how hydroponics can be certified organic since organic
> fertilizers are real no-no's in hydroponics for reasons of sanitation.

I don't understand the whole organic thing anyway. Almost everybody thinks "organic
produce" is grown without pesticides. Au contraire, mon frere. One can look up the
California "organic" regulations easily online. "Organic" produce is treated with
"organic" pesticides, some of which have the same neurotoxic mode of action as
"non-organic" pesticides. Because many "organic" pesticides are less effective than
"non-organic" pesticides, often more must be used. I have this information from
California farmers who grow "certified organic" produce for the California market.

> ... sodium vapor lamps still give the most bang for the buck,
> factoring in initial cost.

LEDs have the advantage of low electricity use and very long life expectancy. They can
be selected to emit only desired wavelengths so as not to waste electricty on
wavelengths the plants don't use. LEDs are far too expensive for most hobbyists now,
other than, perhaps, people growing certain crops indoors who don't want the electric
company notifying the police about how high the electric bill is, or who don't want to
attract police helicopters with infrared scanners flying over their neighborhoods
searching for attics that are much warmer than surrounding ones. LEDs will come down in
price and I predict serious indoor growers - the ones who care much more about the
health of their plants rather than the beauty of the setup - will be using pink and blue
LED arrays before long.

I have used a high-pressure sodium light on a fixture with a motor that moved it back
and forth slowly over the growing area. The bulbs run EXTREMELY hot, dangerously so. A
third-degree burn would result immediately from touching a bulb, and it will also
probably explode if touched while illuminated, showering extremely hot glass over one's
body and plants. Cool bulbs should be handled with gloves, since oils from the hand will
burn when the bulb is lit. A little bit of water on the bulb - as might occur if
spritzing plants with a water bottle - will also result in an explosion. I had one bulb
explode in a winter basement setup for no reason I could determine. The noise was
audible upstairs; glass burned many plants and also burned holes in nearby carpet. Had
there been drapes there might have been a house fire. If I had children I would never
use such lights unless in a room with an automatically closing and locking door.

Sodium lights draw a very large amount of electricty, require a special transformer, and
are expensive to buy and run. They heat the room they illuminate much more than do
fluorescent lights of any design; while perhaps advantageous for some plants, this is
not desirable for winter-growing plants. Sodium bulbs also diminish in light output over
time and must be replaced regularly.

Fluorescent tubes are much less dangerous and work well. Considering explosions and
replacing bulbs / tubes yearly or more frequently, I don't believe fluorescents are more
expensive in the long run. They are readily available at any shop that carries mundane
fixtures. I doubt high-intensity sodium lights will be used for growing plants much

Leo Martin
Phoenix Arizona USA

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