lighting change - best bulbs for planted tank?

[Shoppers]

Hello

Have a second hand juwel rio that had been a marine tank at some point, the current bulbs are a marine blue and a bright white. The plants seem to be doing ok but the fish colours change alot, depending where there are in the tank

Would a planted tank suit 2 bulbs the same? Or a better mix of bulbs?

Cheers

Steve

[F15hguy]

I get good growth rates and the best colour in the fish from a 1-1 ratio of 'Sunlight' and 'Tropical' Lights

[GrahamC]

Green yellow light is apparently best for aquatic plants. Blue light is apparently best for photosynthesis but that gets taken out by dissolved organic compounds. Reds get absorbed by the water. So, aquatic plants use what's left.

[F15hguy]

don't plants reflect most of the green light, hence the green appearance?

[GrahamC]

http://www.hagen.com/pdf/aquatic/GLO-Lighting-Guide.pdf

Check out page 4

[F15hguy]

hrmmm. but if they are green they are obviously reflecting and not absorbing, agreed the other pigments may absorb them.

http://www.sas.upenn.edu/~msheila/Microsoft%20Word%20-%20Why%20are%20plants%20green.pdf

[F15hguy]

Lighting for a planted tank should not be chosen on color temp alone. It is true that 'full spectrum' bulbs are referred to as bulbs between 5000 Kelvin (K) and 6500 K and are considered to be best for planted tanks. Yet this does not indicate what wavelength in nanometers the bulb is actually emitting. If you want to optimize plant leaf development (blue light) and stem elongation and color (red light) you need light in both the blue and red spectra for photosynthesis. You need a mix of blue and red for your plants, and green for you (brightness as perceived by humans). If your lighting looks extremely bright and your plants seem ultra-green, it means that you have lighting that outputs strongly in the green spectrum. Do not equate this with good lighting for your plants, because plants don't use light in the green spectrum for photosynthesis. Sunlight peaks in the blue spectrum at 475 nanometers (nm). This is a shorter wavelength than red light and is used by both plants and algae. As light passes through water the intensity decreases. The shorter wavelength blue light penetrates water better and more quickly than red, which is slower and absorbed more quickly. Chlorophyll, the photosynthetic pigment used by plants traps blue and red light but is more efficient with red light at 650 – 675nm. Blue is used at the same rate as red because it is more available for reasons mentioned above.

from http://www.aquaticplantcentral.com/foru ... hesis.html

[GrahamC]

Yes, as mentioned above, what is best for photosynthesis is not necessarily what the plant ends up using as it has to compete with absorption by water and dissolved organic compounds. And you'll have both of the latter in a planted tank.

[F15hguy]

but if the plant appears green then it is not absorbing green light, if it was it would appear red or purple

If your lighting looks extremely bright and your plants seem ultra-green, it means that you have lighting that outputs strongly in the green spectrum. Do not equate this with good lighting for your plants, because plants don't use light in the green spectrum for photosynthesis.

[GrahamC]

No, not true. It is reflecting some green light but not all. Different parts of the leaf can use different parts of the light spectrum.

See also this discussion http://www.barrreport.com/showthread.ph ... some-cases

[GrahamC]

Green Light Drives Leaf Photosynthesis More Efficiently than Red Light in Strong White Light: Revisiting the Enigmatic Question of Why Leaves are Green

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

Talks about the differential use of lighting spectra within a leaf

[F15hguy]

Effects of Blue, Red, and Green Light on Photosynthesis

Craig Owens and Marsha No

CU Boulder, Fall 2008

For our experiment we tested the question, “What is the relative rate of photosynthesis under red, green, and blue light of Juniper needles?” Our hypothesis is that the color of light is directly related to the rate of photosynthesis. A prior experiment has shown that plants absorb the most light in the blue wavelength range while reflecting the green wavelength range. Taking this into account, we predicted blue light to have the highest relative rate of photosynthesis.

To test our hypothesis, we measured the rate of CO2 change in a container with 0.65 grams of juniper needles under blue, red, and green light. We performed 3 trials, designating 10 minutes, to observe the change in the light and dark. We began our experiment with foil around the container to remove the light and eliminate any initial photosynthesis. Knowing that respiration occurs at all times, we manipulated the data to retrieve the rate of photosynthesis by using the equation; (Photosynthesis+Respiration) - (Respiration) which gave us the amount of CO2 depletion and thus the net photosynthesis rate.

After gathering our data and comparing our results with previous experiments and primary sources, we discovered that red light actually had the highest rate of photosynthesis with an average rate of -0.1525 ppm/g/min while blue light had an average rate of -0.0805 ppm/g/min and green light had an average rate of -0.0192 ppm/g/min. It is important to note that the greater the negative value is, the greater the decrease in CO2 content, in turn increasing the rate of photosynthesis. A t-test comparing the rate of photosynthesis between the red and blue light gave us a P-value of 0.976 which is much greater than 0.05, meaning that there is no significant difference in photosynthesis rate between red and blue light.

[F15hguy]

from your own link to a previous discussion shows several articles and links to articles that show proof that green light is of very low yield to plants, the article stated previously comes to the conclusion that different parts of the leaf absorb different lights, and seems to be more of a proof that plants do absorb some green light, it makes sense that the underside of the leaves are better at absorbing green light than those above as that is the light they are most exposed to.

But you seem to have missed the studies suggesting that the use of green light can actually stunt plant growth and the results from those experiment that show that red or blue light produces better yields in several different species.

so the total conclusion is that to make your plants grow really well, use bulbs high in both red and blue spectrum, but if you want them to look pretty as well make sure you include green or they will not reflect any light to please your senses.

[F15hguy]

and for further proof....

Moreover, it appears that the photosynthesis-independent component in the green light response is influenced by the growth environment. In our previous study, we highlighted that the abaxial stomata, not the adaxial stomata, are able to respond to green light (Wang et al. 2008). We hypothesized that this green light response would be meaningful as acclimation to the transmitted light environment. In the present study, we tested this hypothesis by inversion of the leaves. It was shown that the adaxial stomata could not become responsive to green light by the inversion treatment, and that the green light response of the abaxial stomata was decreased by acclimation to the direct strong light (Fig. 4c). It is probable that the adaxial stomata inherently do not have the capacity for a green light response, which would explain why the change in the growth light environment by inversion failed to induce a green light response. On the other hand, the green light response of the abaxial stomata was weakened by the strong direct light treatment, implying that acclimation to strong direct light eliminates the sensitivity to green light in the abaxial stomata. Moreover, in the inverted leaves treated with DCMU, Gs did not increase in response to green light (Fig. 6c), implying that, in the abaxial stomata, acclimated to strong light with the full spectrum, the photosynthesis-independent response pathway was suppressed.

from http://pcp.oxfordjournals.org/content/52/3/479.full

written by one of the authors from your previously linked article (this is one of the experiments to prove the hypothesis put forward in that article)

[amtiskaw]

http://www.hagen.com/pdf/aquatic/GLO-Lighting-Guide.pdf

Check out page 4

Actually, page 17 says:

Freshwater Plant Growth Aquarium Bulb

Flora-Glo is strongly recommended in planted

aquariums to ensure a broad red and blue spectral

presence,beneficial for photosynthesis in plants.

•Photosynthetic spectrum, ideal for planted

aquariums and terrariums

•Stimulates plant growth

•Recommended in combination with Sun-Glo or Life-Glo

I'm with F15hguy on this one

[GrahamC]

Quoted from Aqua Journal:

In the tropical streams where aquatic plants grow, sunlight are filtered through many vertical layers of tree canopy. The upper layer receives as much as 25% to 100% direct exposure to sunlight. This is scientifically known as the euphotic layer. In the lower parts of the forest and streams below, where low light conditions occurs, this is known as the oligophotic layer where a mere 1-3 percent of light is made available to plants. This small percentage of light are filtered through the forest green canopy and reflected as incidental light, thus the natural wavelengths are dramatically altered. Aquatic plants have evolved millions of years to adapt to greenish light available to them. The NA-Lamp adopts a fresh green ulothrix fluorescent to reproduce nature's green irradiance wavelength in your aquarium.

Yes, blue and reds will max out photosynthesis if the plants can get it. But as I mentioned above, reds are absorbed by water and blue by dissolved organic compounds. As I understand it Amano feels you'll get more natural growth patterns with green lighting which is why they sell green lighting. they also have blue lighting but I believe it's for marine tanks.

[F15hguy]

Well, I've had more than few run ins over this topic about the middle bans being used by plants and that the Red/blue spikes are appealing to some fol's eyes, but they do not significantly make the light bulb more efficient and have a higher PUR etc.

They use other pigments to grab this light as it filters through the tissue and the epidermis.

Amano/ ADA suggested filtering from the forest around the aquatic plants, but few, hardly any aquatic plants lie in such dark locations in forest, they live mostly in open marshes...........

They could have stated this citation, or said what these authors said, rather than that bull manure.

It still shows the light works well in those color ranges/nm etc.

Just their reasons for it working are simply put, wrong.

Now some plants, like Egeria and myriophyllums etc are only 2-3 cells thick on their leaves, so the filtering of the light is not great, but the filtering of red light is in water...........and Green algae are around, so that also absorbs some like the forets/trees etc like ADa claimed, again, missing the other things that are present in nature.

I really kind of hate ADA's "nature" poem crap, it's really not very nature oriented Science wise. If you hold such respect for nature, then you learn why, how it works, what things cause it to be the way that it is, not some poem about what you'd like it to be.

Big difference.

from the barr report that you linked us to.

The blue light is better for marine tanks as blue light penetrates deeper and provides a better quality light for the photosynthetic algae in corals. (and red light disapears a lot quicker in marine water.)

also I believe the only real reason they sell green lighting is to be used in conjunction with red lighting to provide the 'glowing' look people like in their tanks (try it out and switch each colour on and off individually) hence my preference for multipletubes with different wavelengths (p.s. look at amano's tank specs in his nature aquarium books, he doesn't use green lighting)

Yes, blue and reds will max out photosynthesis if the plants can get it.

then why not give it to them???? the original question was what type of light provides the best growth.

[GrahamC]

then why not give it to them???? the original question was what type of light provides the best growth.

Sunlight.

But if you want the most natural growth, yellow green.

And if you want maximal growth no matter what it looks like, blue red

[Godly3vil]

:slfg: :spop:

[GrahamC]

(p.s. look at amano's tank specs in his nature aquarium books, he doesn't use green lighting)

Which book?

Aquarium Plant Paradise - he uses sodium tubes ( yellow )

Nature Aquarium World Books 2 & 3, he just quotes wattage and photoperiods.

[F15hguy]

Which book?

Aquarium Plant Paradise - he uses sodium tubes ( yellow )

Nature Aquarium World Books 2 & 3, he just quotes wattage and photoperiods.

I stand corrected.

But as I mentioned above, reds are absorbed by water and blue by dissolved organic compounds. As I understand it Amano feels you'll get more natural growth patterns with green lighting which is why they sell green lighting.

I don't believe that its for more natural growth,

NA Lamp with an additional green spectrum.

The New NA Lamp has the highest peak at 540

nanometer and another peak at 520 nanometer

(see the arrow in the illustration above). This

new sub-peak is adopted to bring out the most

natural colours of the aquatic plants.

from the ADA australia website, I read this as it provides the best Veiwing of the plants, i.e. it provides the green light to make the plants prettier to the human eye.

also most plants do not come from a poetic forest floor area, most come from lakes and marsh areas in water less than 2m deep, so the effect of water absorbing the light is very minimal. if a plant come from these areas they are normally sciophytic and grow in areas of the tank that should be shaded from above by other plants, naturally filtering and reflecting the light to a more green wavelength anyway.

The only thing I can see is that they purposefully chose to reduce the light intensity so that folks would get slower growth, but less issues with a wider range of public dosing routines when using their brand of lights.

So more folks would have less algae and dosing issues with their lights, while others would have more hassle using other brands.

from the Barr report

or you could just look at what light chlorophyl absorbs, as proven many times over by science....

[F15hguy]

an interesting quote ....

Hrmm...

If what Amano researched is indeed true, we all can just use ordinary shop bulbs.

In shop lighting, the light's selling point is the brightness. Manufacturers purposely exploit this to the human's eye spectrum sensitivity, and create a huge spike on the green region. The reason is because the green spectrum is the most sensitive region to the human eye. Thus inserting a lot of green, would make bulbs appear to be brighter.

[GrahamC]

We do know the absorption characteristics of cholorophyll a & b in laboratory conditions for terrestrial plants but what the above data is not showing is what happens in the tank. And we do know that aquatic plants do have adaptations to absorb green light, and there are parts of the plant that utilize light in different spectra. Practically speaking though I would just follow the recommendations of those who are acknowledged experts in creating great planted tanks.

Here's an article by Amano for the OP http://www.tfhmagazine.com/details/arti ... uarium.htm

[F15hguy]

agreed, they are far more knowledgable than I, but i prefer to learn from as many as possible than listen to just one

[F15hguy]

and a lot of feedback shows that the ADA system is more about marketing and looks than actual science.

http://www.plantedtank.net/forums/showthread.php?t=77551