PHOTOSYNTHESIS

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what are the wavelengths that plants need to produce energy? do they
need uv-a and uv-b light or is normal light enough?

[Richard Sexton]

In article om>,
> wrote:
>what are the wavelengths that plants need to produce energy?

"Red and blue". It's a bit more complicated that that though;
the two primary photosynthetic pigments are chlorophyl A
and B. THeir absobtion peaks are at 430nm,662nm and 453nm,642nm
respectively.

But there are other photosynthetic pigments, that is the
range of light that results in photosynthesis does not
exactly match the absobrtion spectra of chlorophyll.

Caratinoids, whihc are red, orange and yellow in color
have their maximum absobrtion bewteen 460nm and 550nm.

>do they need uv-a and uv-b light or is normal light enough?

UV stunts plant growth.

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[[email protected]]

wrote:
> what are the wavelengths that plants need to produce energy? do they
> need uv-a and uv-b light or is normal light enough?

400-700nm
No they do not need UV-a or b and normal light?
Not sure what normal light "is".

Plants possess a number of pigments and if you look at O2 evolution
over the spectrum, 400-700 nm is the usable active radiation
wavelengths.

While max absorptions levels are often mentioned, the reality is that
O2 prodouction is fairly stable throughout this range.

All light energy falls into the 2 reactions centers as P680*nm or
P700*nm to run photosynthesis.

Anything above that is fine. Plants can and do adapt their pigments to
catch whatever is available.

Regards,
Tom Barr

[Watercress]

Go to website of specialty fluorescent tube, for that for the Zoo-med
tubes. They have nice chart and everything.

And to answer your question, normal light is not enough. I assume you
mean normal fluorescent light. The good news is the specialty tubes
are not that expensive. I got my Zoo-med at about $8 a piece.

Incidentally, since you are asking this question, you probably have not
started this hobby. I just want to tell you that this hobby can be
quite time consuming, compared to say, just keeping a few topical fish.

[Richard Sexton]

>Plants possess a number of pigments and if you look at O2 evolution
>over the spectrum, 400-700 nm is the usable active radiation
>wavelengths.

I'd suspect a two equivalent tanks one with green plants
and one with all very red plants (ie Alterneranthia) would
have different optimal absorbtion spectra though.

Not by much though if this is any indication:
http://www.msu.edu/course/lbs/145/luckie/inquiries2003/PepsinPals.html


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[Richard Sexton]

>And to answer your question, normal light is not enough. I assume you
>mean normal fluorescent light. The good news is the specialty tubes
>are not that expensive. I got my Zoo-med at about $8 a piece.

Eh. A $2 warm white and a $2 cool white is fine. It's relaly a diminshed
return other than aesthetics if you spend even a tiny bit more.

>Incidentally, since you are asking this question, you probably have not
>started this hobby. I just want to tell you that this hobby can be
>quite time consuming, compared to say, just keeping a few topical fish.

Doesn't have to be.


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[Watercress]

$2? Where do you shop? I can't get those prices at Home Depot. The
normal tube are about $6 a piece I think. As for normal light, my
understanding is that it contains spectrum between red and blue. It
makes the light look brighter but encourages algae growth. Well, at
least that was what I read. The chart of that Zoo-med Flora Sun tube
showed two humps one at red and one at blue. To my eyes, the light
looked dim and unappealing, but my plants seem to like it.

Well, if you keep hardy fish in a fish only tank, you only need to do
weekly water changes and filter cleaning. To control algae, you only
need to keep the lights off when you are not viewing the fish. I don't
have to list what we need to do to keep our planted tanks thriving and
beautiful.

[Richard Sexton]

In article om>,
Watercress > wrote:
>$2? Where do you shop? I can't get those prices at Home Depot. The
>normal tube are about $6 a piece I think. As for normal light, my
>understanding is that it contains spectrum between red and blue. It
>makes the light look brighter but encourages algae growth. Well, at
>least that was what I read. The chart of that Zoo-med Flora Sun tube
>showed two humps one at red and one at blue. To my eyes, the light
>looked dim and unappealing, but my plants seem to like it.

Maybe it was a sale or something but there were $1.99 cool white
and warm white tubes at Home Depot around xmas.

Green makes tubes look brighter, not red or blue. But plants
can more easily utilize red and blue.

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