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Light spectrum tweaking help for optimal growth

Gilles

Gilles

Member
Joined
29 Mar 2011
Messages
116
Please find attached a color spectrum of the lights i currently have. As you can see by the graphic, i can tweak each channel to my likings, resulting in a different spectrum, a different output in Lumen and a different wattage.

I also have the possibility to show Clorophyl A, Clorophyl B and Violaxanthin as overlays. However, i do not know what they mean or if they are for instance only applicable to sea water (which i assume Violaxanthin is, due to the fact that it is in the blue area). I did not activate the human sensitivity overlay; which is basically a curve between 485 and 660. Can someone please shed some light (hehe) for me on this graph? Where should my peaks be when i am aiming for maximum growth in Freshwater plants? Should i max out all channels and go for the most "lm" or should i focus on the wavelengths?

I might be overthinking it but i would really like to learn some theory in this area.

attachment.php
 
I also wonder if my BGA which still occurs even after doubling the NO3 in my EI mix caused by some wavelength i am pushing... ?
 
yep, any colour that looks good to you. I have chopped and changed the colour spectrum from my futura no end over the last year and it makes zero noticeable difference to growth. Just use what you like... personally i like the greens to pop which means my red and green leds run much higher than the whites, yellows, purples and blues.
 
Gilles said:
Please find attached a color spectrum of the lights i currently have. As you can see by the graphic, i can tweak each channel to my likings, resulting in a different spectrum, a different output in Lumen and a different wattage.

I also have the possibility to show Clorophyl A, Clorophyl B and Violaxanthin as overlays. However, i do not know what they mean or if they are for instance only applicable to sea water (which i assume Violaxanthin is, due to the fact that it is in the blue area). I did not activate the human sensitivity overlay; which is basically a curve between 485 and 660. Can someone please shed some light (hehe) for me on this graph? Where should my peaks be when i am aiming for maximum growth in Freshwater plants? Should i max out all channels and go for the most "lm" or should i focus on the wavelengths?

I might be overthinking it but i would really like to learn some theory in this area.

attachment.php
Click to expand...

Keeping in mind that all else is good and you really feel that the correct spectrum will be of some benefit .
Green reflects light and red absorbs it , 650 nm is the optimum wavelength but can you look at that color in your tank ?
I removed my 650nm bulbs and replaced with daylight 6500k; sure the growth may not be perfect but what is now and days :)
 
@ceg4048 after thoroughly reading the following sites;
1) http://www.hallman.org/plant/huebert.html
2) http://www.aquaticplantcentral.com/forumapc/lighting/38014-lighting-spectrum-photosythesis.html

Especially after reading (2) i am now more knowledgable on the subject and i can see how i can adjust my lights;
Plants will grow with ordinary bulbs as they tend to have both some blue and red emissions. The problem is that they also have wavelengths between 500 and 600nm, which algae likes. Green algae and green plants use the same pigments for photosynthesis (chlorophyll a/b & carotenoids). So, light that helps one helps the other. The algae that are different are the blue-green algae (cyanobacteria), which contain Phycocyanin and absorb light heavily in the low 600nm (orange-red), which is unfortunately present in most standard fluorescents. In the planted aquariumartificial light should ideally peak (or be stronger) in the red area of the spectrum. The tanks’ appearance can be compensated (balanced) with blue light and some green light for brightness to the human eye. Strong blue light will cause plant growth to be more compact and bushy and will also tend to promote algae growth. So remember to balance 2/3 red to 1/3 blue light emissions.
Click to expand...

Current assumptions made:
1) Green increases the brightness and thus the lumen (since Lumen is in the human visible range)
2) Kelvin says nothing about light colors.
3) My LEDs won't peak near 675nm
4) Since i have light in the low 600's this might be causing my BGA; but i can only find out if i remove that light.

Well i don't know it it will work for my case but i'll just see what i can figure out :)
 
The links you gave are very old and outdated now, many people had since proved that light in fact any light makes the plants grow. Just choose a tube that makes your plants look nice.

Look at the pictures here, choose what you think looks best and buy the tubes.
http://www.ukaps.org/forum/threads/cheap-ho-t5-fluorescent-tubes-update-with-photos.555/

This is a good site, and good comments on lights. He picks up that marketing departments now define the "spectrum that makes plants grow" rather than the engineering section.
http://www.skepticalaquarist.com/fluorescent-light
 
Wavelength will not save you from BGA and it will never be the cause of BGA. People get BGA using every kind of light bulb there is. Conversely, there are those that do not suffer BGA no matter what bulb they use, so it's best to forget all that because it leads nowhere.

Cheers,
 
Actually remembering back to a book I read years ago about growing things one shouldn't grow, it mentioned that red light is best for growing plants.

This is confirmed by the results here (and numerous other places).
http://www.plantingscience.org/index.php?module=pagesetter&func=viewpub&tid=2&pid=1760

However, I suspect using just red will make your aquarium look like something from Amsterdam red light district, but with great plant growth.

Industrially hydroponic users can & do use red lights (LED & yellow), but it is hard working in these environments, everything is either red or black, making care of plants difficult, as well as affecting human vision perception of depth so that people are "clumsy". So other colour light is added, usually green, purely making it easier environment to work in. Very handily sodium (both high and low pressure) lights have lots of red, and some other colours, and are very energy efficient which is why certain naughty people use them to grow plants in their houses.

So my suggestion for best "Light spectrum tweaking help for optimal growth plant growth" and also a very efficient light source would be a sodium lamp. Job done. Question answered. :D
 
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