actinic lighting vs algae growth

ceg4048

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Mortis said:
.. they can only absord those two and not green which they would reflect.
This is not entirely true. Plants use all visible wavelengths depending on the environmental conditions. Let's not compound one myth with another.

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Mortis

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Yeah, your right I guess. Plants just use the photons from light for photosynthesis right ?
 

ceg4048

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Mortis said:
Yeah, your right I guess. Plants just use the photons from light for photosynthesis right ?
Correct! The mechanism of photon assimilation is summarized in the thread PL-11 Tubes

More details about spectral quality in the thread Bit lost in the Luminaire Jungle and Looking for neutral colour T8 tubes

If one is worried about algae, it'd be a better idea to forget about spectral issues completely and concentrate more on understanding the principles discussed in the thread Why don't nutrients cause algae? because it's almost a certainty that the people who are programmed by The Matrix to worry about spectral quality have also been programmed to worry about nutrients. A diabolical combination of misinformation. I advise to take the Red Pill...

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Mortis

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Yay ! But plants do prefer light in the blue/red spectrums right ? Are the photons in a 'better' energy state at these wavelengths ?
 

ceg4048

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Well it's not good to think in terms of "better", otherwise we fall into the same trap as our brethren trapped in The Matrix. Blue and red are the fundamental frequencies. Blue is so abundant and has high energy levels so the plants use a system of blue sensors, called Cryptochromes, to control things such as chlorophyll synthesis, stomatal opening and even phototropism (the direction of growth, or the tracking of the light).

Red is used for various other sensor data. This is referred to as Phytochrome system. Phytochromes are proteins which respond to incident red. Phytochromes have their own special pigments called chromophores, and they change their protein structure based on the specific wavelength of the red. Different responses occur based on the type of structural change of the protein. For example the level of red can tell the plant whether it's in shade and the degree of shading to which an individual leaf (or the plant as a whole) is subject to. So this governs response and behavior, even optimization of nutrient uptake mechanisms. As a result of this sensor data, there will be specific conformational changes such as elongation of stem, leaf shape change and so forth.

So you see it's not a matter of "better" or "worse"... that's an illusion. It's simply a mater of how individual species allocate their resources in response to the environment based on the light provided. If you decide that you love looking at a pink tank then use 100% Grolux type lights and the plants will make the adaptation based on what they sense and will reallocate their resources to match the Grolux. If you decide that you prefer Marine Actinic, or Daylight, or a combination, then the same will occur. As long as you are above the LCP and are providing adequate levels of CO2 for the given photon flux density, the adjustments will be made. Remember that auxiliary pigments have the ability to change the incident wavelengths by absorption and fluorescing. This is easily done by adjusting the energy levels of electrons within the pigment structure.

I can grow plants just fine using standard office bulbs which have most of their energy in the yellow/orange. Osram 840 is a classic example. Here is L. aromatica grown pretty much with these goofy orange bulbs until I couldn't stand it any more. All it does is make everything look orange. What's the big deal?
8394102625_6f831836bb_c.jpg


Here is some more grown with a combination of blue and daylight. I don't see any algae due to blue:
8394102025_ebc185cd2d_c.jpg


If you want to use the word "optimum" then sure, make sure you have at least some of the fundamental frequencies blue/red, but don't stress over spectral quality. There are so many other things that will have a palpable effect on growth that spectral quality "pales" in comparison. 8)

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plantbrain

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I've used 50/50 Atins and daylights, they look ugly as Hades.......

They do not really affect any algae or plant growth compared to other lighting.

That's the practical test.
For the theory to be correct, I'd have to see some evidence that they do encourage algae in and of themselves, not due to these bozo clowns on the web who cannot grow plants consistently day to day, who know what caused their algae issue/s?

May have simply been more intensity when switching to Pc lights etc, or newer bulbs etc, nothing to do at all with the spectrum etc. They never demonstrate that nor provide a control for all their banter and rubbish.

They either poo poo the criticism via PM's, or something they are foolishly brave enough to try and justify they have actually demonstrated something and try to argue that. I think the latter is worse.

Socially it is understandable.
Who likes to be told that their myth based advice is wrong and false?
So they often do not go down without a fight :idea:

This is a bit of human nature.
Many stories surround this conflict's theme.
Myth,belief vs the the logical common sense.

I find some BS I've been telling folks is wrong, I go back and make sure, learn more, see if and how I went wrong. Learn and correct it. We all make mistakes, admit it and learn and move on dangit!

Or ye shall be flogged with Cattails till ye howl like the vermin that ye are. :D

Heck, you only make your self better in doing so, and you help your fellow hobbyist.

I do think there is somethings to be said for different colors of bulbs and getting certain aesthetics from the lighting.
I have much better coloration in my T5 tank vs the others with MH's and PC's. PAR's are about the same, a little difference in spread etc. I cannot attribute it to much else other than color. These aesthetics however, much harder to quantify and too find any good research answering such aesthetics based questions.

Rats......



Regards,
Tom Barr
 

sanj

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Thanks for this thread, I am due to move aquarays from my Reef to subtitute some T5 lighting on my planted tank (new LEDs going on the Reef tank). So i was wondering about blue light and thought that plants should be able to utilise and adapt to bluer light from Marine whites, Reef Whites and blues, just that it may not look too good. Then again they would be mixed with T5 6000k so might not look too bad.

Yes there is a lot more Blue light/Actinics grow algae on the net. I would think that would be if they were using blue lights for long periods of time outside the photo period. Hmm...

Clive excellent understandible reasoning as usual. How is the book coming along? You know you should. :)
 

ceg4048

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Yeah, I know, but I'm still stuck on what the title ought to be. I'm thinking something like "Blue Haters & Nutrient Haters - Push Off". :wave:

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plantbrain

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Lisa_Perry75 said:
In strong white light plants can utilise green light for photosynthesis better than red or blue.

http://pcp.oxfordjournals.org/cgi/content/full/50/4/684

ADA's lights are mostly in a green band also.

Reflectance also plays an aesthetic role to our eyes.
Hard to tease those apart for our goals.
I do not think the algae cares much as long as there's some 400-700nm range available.
Same for plants.

Regards,
Tom Barr
 

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