[APD] Actinic light and semantics

["Thomas Barr" <tcbiii at earthlink_net>]

"Plant lamps are designed to emit light at the red
wavelengths to duplicate the job of the sun. But too much
red color can cause aquatic plants to grow tall and thin.
For best results, use a daylight (5,000 K) lamp such as an
Aquasun, Ultralume 50 or Chroma 50 in combination with an
actinic white or actinic day lamp. The actinic day or white
lamp is a mixture of 50% actinic (blue light) and 50%
daylight."

I disagree with him about a 5000K bulb being something that will yield thin
tall growth which is what this statement __seems to suggest___ . He did not
come out and say but the suggestion is very strong.
Some semantics here. "But too much red can cause the plants to grow tall
and thin" .
He did not come out and say 5000K or cool white bulbs cause this type of
growth. 
But it does sound like 5000K causes leggy thin growth doesn't it?

Light bulb makers, Cables, algae miracle cures and all sorts of consumer
products such as the Cladophora pills or Hydrilla pills that turn limpness
into wild sex animals of lust and passion and makers of various snake oils
all tend to play these word games. Spam anmd scams also tends to contain
large amounts of this language.

Folks need to be careful and read what it is that is really being said.
I'd like to see some research __clearly__ showing this to be
significant(5000K vs a 5000K plus an actinic) before I'd believe this
concerning aquatic plants. 
I have my proof to the contrary and my experience using cool whites. I used
a 50:50 daylight, actinic bulb for a couple of years so I know both sides
of this coin. 

Dr Cain(Micro propagation research namely on Orchids and aquatic plants)
uses the cool whites so it's specifically on aquatic plants, Robert Hudson
had dug up a good paper on the use of cool white in growth studies and had
posted it on his site about a year or so ago.

.That is a good study and would be tough to argue against based on folks
experiences and the theory when looking at aquatic plant photosynthesis and
their LHC's.
I have at least a dozen research papers on aquatic photosynthesis sitting
around my place. 

 Actinics have a dagnasty blue spike and not much else(virtually all the
energy is all centered around the blue range(no red, yellow, green at all
pretty much), 10K bulbs and most other bulbs have other portions of the
emission spectrum that balance the blue with red etc.

I'll give him the benefit of doubt and assume he's suggesting that a mix of
bulbs will give a good balance to the eye and the growth of plants. An
Actinic with say several(3) 5000K bulbs would give a good mix perhaps, but
actinics are not particularly useful as they put all the energy into a very
small blue range with not much else which is ideal if you live 10-20 meters
deep in __clear__ water like coral. 

Virtually all aquatic plants live in the top 1-2 meter or so although you
may find them deeper but the best growth is near the surface, not down
deep. Few folks have tanks over 1 meter.

Will actinics hurt?No, will they help more than a 6000-6700 K bulb? No.
Would you be able to tell the difference as a hobbyist between a tank with
2 x 5000K and an Actinic vs a 2x 5000K and 6700K? I doubt it. 5000K and
6500K bulbs are cheap and easy to find, actinics are all specialty bulbs
that generally cost a fair amount more. Marineland owns companies that sell
aquarium specific bulbs. 
If I talk like this much, they'll never hire me:) I was suppose to go talk
to them and meet with the prez a couple of years ago but never got around
to it since I'm not done with school and have other higher paying
plans/goals.

This is a classic type of how many aquarist does it take to screw in a
light bulb type post:)

Regards, 
Tom Barr 


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