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Is there any difference between the color of the lights for planted tank?

CheckeredRust

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I bought one of those overhead aquarium lights where you can switch between 3 options, full white LED, red and blue LED and white, red, blue LED. Is there any difference to use one over the other? Do plants grow better under those red/blue lighting?
 

jamila169

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I can only offer anecdotal evidence that when I added a 3 colour light to my community tank , the plants really took off, whether that was because there was more light overall, or it coincided with them getting a proper foothold, or they really do like the 3 colours better I couldn't say (though specific plant growth lights tend to have a mix of WRBG, so maybe it does make a difference to add some different colours?)
 

dino21

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Red/blue seems to work well out of the water, so one would think it would do for submerged plants, but what effect the water depth has on these colours for home aquarium use of mainly under 1 mtr ?

TwinStar states their- " LED offers an optimum range of wavelengths of 400nm to 700nm which is exactly what plants need to thrive and flourish"

Colors visible to the human eye are found at the following approximate wavelengths:
• Violets and Blues between 400 nm and 480 nm
• Greens between 480 nm and 560 nm
• Yellows between 560 nm and 590 nm
• Oranges between 590 nm and 630 nm
• Red between 630 nm and 700 nm

Would be very interesting to hear some qualified answers
 

MichaelJ

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I bought one of those overhead aquarium lights where you can switch between 3 options, full white LED, red and blue LED and white, red, blue LED. Is there any difference to use one over the other? Do plants grow better under those red/blue lighting?
Yes, the the plants absorption is much higher at the blue (mid 400 nm) and red ends (mid 600 nm) of the spectrum.. The middle part (green) of the spectrum is mostly reflected, hence the green appearance of the plants.
Cheers,
Michael
 

MichaelJ

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I cant say that i actually know but there a lot of post on this forum stating that the colour spectrum has very little effect on plant growth!
That is definitely true as far as "Color Temperature" and Kelvin rating is concerned - which is most often unrelated to the spectrum distribution. I.e. you can have a 2 lights that appear exactly the same color temperature (say Daylight 6500 K) with vastly different spectral power distributions. What you want is light that covers (i.e emits energy across) the full spectrum to a reasonable extent - the color temperature is more an esthetic consideration.

Cheers,
Michael
 

Nick potts

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That is definitely true as far as "Color Temperature" and Kelvin rating is concerned - which is most often unrelated to the spectrum distribution. I.e. you can have a 2 lights that appear exactly the same color temperature (say Daylight 6500 K) with vastly different spectral power distributions. What you want is light that covers (i.e emits energy across) the full spectrum to a reasonable extent - the color temperature is more an esthetic consideration.

Cheers,
Michael

I always thought that spectrum and the colour/look of the bulb (Kelvin) were linked, it made sense to me that light with a big spike in the 460nm range would have a blue look and hence a higher kelvin rating, is that not the case?

As to the original posters question, in most situations, the only practical difference apart from how the light looks will b the fact that having all colour LEDs on will have increase light output so more par etc
 

MichaelJ

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@Nick potts No your right, but I was trying to make the point that for plants it's really more about the energy distribution than the color/tone of the light. Plants are just as fine with a full spectrum light source at 4000K source as they are with a full spectrum light source at 8000K - both light sources will cover the full spectrum but will of course look different and may need to be dialed in differently with respect to intensity.
Cheers,
Michael
 

ceg4048

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I bought one of those overhead aquarium lights where you can switch between 3 options, full white LED, red and blue LED and white, red, blue LED. Is there any difference to use one over the other? Do plants grow better under those red/blue lighting?
Hello,
There is no difference between any color light that you may choose to use. As mentioned, the subject has been thoroughly discussed and no one has any evidence in our tanks that spectrum has any value other than an aesthetic one. Plants simply adapt to the lighting provided and they have very clever ways of converting incident colors to colors they can use. They also have clever ways of blocking excessive energy from those colors, but this mechanism can easily be defeated by hobbyists who insist on using extreme energy lighting. What matters most to plants is the incident level of PAR (Photosynthetically Active Radiation). Changing the spectrum may have some minimal effect until the plants make the adaptation to the new light source. If you change the spectrum and if the new spectrum has a lower PAR then the growth rate. is reduced. If you change the spectrum to one with higher PAR then growth rate increases. Since different color bulbs will have different PAR output any changes you make must be interpreted within the context of the PAR output level.

Cheers,
 

Aquahorti

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There is a huge difference between lights, and how well the plants will grow under them.
For some reason there is a very widespread misunderstanding that RGB lights are good for use in aquariums, and that all you need to worry about is the PAR of a given light.

You get the PAR reading by meassuring the energy output between 400 nm and 700 nm, and it will tell you nothing about the spectral power distribution of the light. The spectral power distribution is important, as lights that look white to our eyes might be a mixture of wavelengths that are far from the optimal wavelengths for the plants needs. An example of this could be the extreme case of the white laser from the experiment done by Jeff Tsao in 2011 where they produced what to the human eye looked like white light, but it was made by mixing 4 narrow band lasers. This light would not be very good for plants, but have a high PAR reading and make the colors pop. Granted this is not something you would run into as a light sold for use in the aquarium hobby, but serves as a argumentum ad absurdum.
I recommend reading the wiki entry on PAR, it is a good starting point and easy to read. The links in it are in some cases a bit on the old side but for the average person in the hobby it will do.

As to the claim that the spectral power distribution have very little effect on plant growth. If you look at real articles outside the hobby, you will find an abundance, showing that this is not the case, so people should stop perpetuating this misinformation.

As to the notion that Kelvin and spectral power distribution are somewhat linked, you are correct, but remember that Kelvin again is linked into the human eye and the way we see, so all it really tells you is what part of the spectrum is dominant. This means that the Kelvin rating of light doesn’t mean that the light is any good for growing the plants you have in your aquarium.

The best thing you can do for your plants is get lights that are as close to the spectral power distribution of the sun at earths surface as possible. The problem with those are, that they are not cheap, but in my mind they are really worth it. I use the VTC series from Yuji, and have some of the BC series lights even though they are not quite as good as the VTC series but still better than most other lights on the market.
 

DTM61

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There is a huge difference between lights, and how well the plants will grow under them.
For some reason there is a very widespread misunderstanding that RGB lights are good for use in aquariums, and that all you need to worry about is the PAR of a given light.

You get the PAR reading by meassuring the energy output between 400 nm and 700 nm, and it will tell you nothing about the spectral power distribution of the light. The spectral power distribution is important, as lights that look white to our eyes might be a mixture of wavelengths that are far from the optimal wavelengths for the plants needs. An example of this could be the extreme case of the white laser from the experiment done by Jeff Tsao in 2011 where they produced what to the human eye looked like white light, but it was made by mixing 4 narrow band lasers. This light would not be very good for plants, but have a high PAR reading and make the colors pop. Granted this is not something you would run into as a light sold for use in the aquarium hobby, but serves as a argumentum ad absurdum.
I recommend reading the wiki entry on PAR, it is a good starting point and easy to read. The links in it are in some cases a bit on the old side but for the average person in the hobby it will do.

As to the claim that the spectral power distribution have very little effect on plant growth. If you look at real articles outside the hobby, you will find an abundance, showing that this is not the case, so people should stop perpetuating this misinformation.

As to the notion that Kelvin and spectral power distribution are somewhat linked, you are correct, but remember that Kelvin again is linked into the human eye and the way we see, so all it really tells you is what part of the spectrum is dominant. This means that the Kelvin rating of light doesn’t mean that the light is any good for growing the plants you have in your aquarium.

The best thing you can do for your plants is get lights that are as close to the spectral power distribution of the sun at earths surface as possible. The problem with those are, that they are not cheap, but in my mind they are really worth it. I use the VTC series from Yuji, and have some of the BC series lights even though they are not quite as good as the VTC series but still better than most other lights on the market.
Hi,

Interesting. What lights do you use? Homemade with specific LEDs? I'm struggling to find anything prebuilt but I've only done a quick search. Alternatively, has there been any investigation into the highest CRI aquarium lighting? My apologies, its a new term for me but obviously I'm interested in what's best for the plants and for my eyes!

Cheers
Dan
 

MichaelJ

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As to the claim that the spectral power distribution have very little effect on plant growth. If you look at real articles outside the hobby, you will find an abundance, showing that this is not the case, so people should stop perpetuating this misinformation.
@Aquahorti Not sure anyone actually alluded to that notion... I certainly believe that your doing your plants a favor by growing them under light that emits a significant amount of energy across the full spectrum of the PAR range (~400-700 nm). The ratio between the blue/red part (roughly the hue/tone) won’t matter much if at all, but I don’t see why the plants wouldn’t be better off with the full spectrum, similar to what sun light provides, versus say a light source that emits a giant spike around 450nm and a lump around 650nm - which is quite common for a typical daylight designated light bulb. Obviously you won't be doing your plants much good by growing them under extreme narrow band light at the edge of the PAR range. No one would use such light with an aquarium anyway.... All that being said, what usually causes the light induced troubles (algae, poor plant health), and what hobbyists should probably be more concerned about, is not the constituent of the light but rather the intensity. That's usually what causes the trouble and much less the spectral energy distribution emitted by the light source.

Cheers,
Michael
 
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Aquahorti

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@Aquahorti Not sure anyone actually alluded to that notion...
and yet that is what is stated in the first line in the post above mine…

Sorry, but you are wrong, even people who are just doing this as a hobby should worry about the spectral power distribution.

I have tested aquarium lights that dispite being dimable were only able to keep easy plants alive at the lower settings, while algae thrived. Once I started testing it at higher settings of the intensity, the plants started to grow, but not very well. The algae would still grow at the higher settings but because the plants were now growing as well, it was possible to make the aquarium look quasi OK. The problem was not the energy output, it was the spectral power distribution.

As to your claim that the green part of the spectrum does not matter much to the overall health of the plants, I suggest looking up Relative Quantum Efficiency, as well as read up on how the different wavelengths influences plant morphology.
 

Nick potts

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and yet that is what is stated in the first line in the post above mine…

Sorry, but you are wrong, even people who are just doing this as a hobby should worry about the spectral power distribution.

I suggest looking up Relative Quantum Efficiency, as well as read up on how the different wavelengths influences plant morphology.

While I agree that certain spectrums probably are better for plant growth than some others, most hobbyists aren't going to read up on Relative Quantum Efficiency and IMO there is no need to. Stick with a known light that is shown to grow plants fine and you wont go far wrong really, doesn't need to be expensive either, there are plenty of budget lights that are capable of growing any plant available to the hobbiest. The time and energy is better spent understanding general husbandry and other aspects of keeping a thriving aquarium.
 

Aquahorti

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Hi,

Interesting. What lights do you use? Homemade with specific LEDs? I'm struggling to find anything prebuilt but I've only done a quick search. Alternatively, has there been any investigation into the highest CRI aquarium lighting? My apologies, its a new term for me but obviously I'm interested in what's best for the plants and for my eyes!

Cheers
Dan
I have after years of trying to get lights for my aquariums from many of the more well known brands in the hobby given up and had to make them, using strips and COBs. I know that it is possible to get T8 LED tubes that will fit some fixtures but they do not fit in with my setups.

Regarding CRI, you can get lights with very different spectral power distributions, but they still have CRIs in the 95 to 98 range.
Just remember that there are many lights that will do just fine and it does not have to be a minor science project to get the right light. That being said I have found that the closer I have managed to get to the solar spectral power distribution, the less work I have had to do in my aquariums (besides trimming plants).
 

MichaelJ

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and yet that is what is stated in the first line in the post above mine…
Well, that is your interpretation of what @ceg4048 was conveying.
Sorry, but you are wrong, even people who are just doing this as a hobby should worry about the spectral power distribution.
I never claimed that it is not important... as a matter of fact in my posts above I stated that I believe in full spectrum light being beneficial to plant health.... so I am not entirely sure how I am "wrong" -- As we are all fully aware we are dealing with a tremendous amount of variables in this hobby. You might have experienced insufficient spectral power distribution as the culprit... My experience is the opposite... too much light causing algae growth and poor plant health... so there is that. What I generally would love in this hobby is more hard peer reviewed science on all the aspects of fish and plant keeping.
As to your claim that the green part of the spectrum does not matter much to the overall health of the plants, I suggest looking up Relative Quantum Efficiency, as well as read up on how the different wavelengths influences plant morphology.
I never said such a thing - and I actually think it is a bit rude to misrepresent what I said in that way. And next time you tell people go read up on a subject matter I suggest you provide some hints, links or pointers, instead of just brushing people off by trying to sound smart.

We are all trying to educate ourselves here.
 
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Wookii

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I think @ceg4048 is spot on - the spectrum produced by the light is largely irrelevant, outside of any extremes (e.g. you might encounter issues trying to grow plants under a UV light), as long as the light produced is generally within the range of white light colour temperatures. This is clearly evidenced by the huge range of lights members on this forum alone use to successfully grow aquarium plants, from LED flood lights to LED tape to dedicated marine lights.

I'd be willing to accept there may be certain lights that 'maximise' plant growth, such as hydroponic lights with only red and blue output, but in an aquarium we're not looking to maximise production of plant mass growth for commercial purposes, but simply to grow clean healthy plants, and aesthetics of the illuminated tank are going to be equally important.

Ultimately the overriding advice has got to be pick a light which fits your budget, tank requirements and chosen aesthetics, and don't worry much beyond that.
 
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ceg4048

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As to the claim that the spectral power distribution have very little effect on plant growth. If you look at real articles outside the hobby, you will find an abundance, showing that this is not the case, so people should stop perpetuating this misinformation.
Yes, but again we are not growing plants outside the hobby. We are growing plants within the context of our hobby and in so doing it turns out that there are so many more factors that affect the growth and health of aquatic plants that the effects of spectral distribution are rendered irrelevant. As I mentioned, no one has been able to show any differences in plants grown with any bulb with a specific spectral distribution versus any other bulb having a different spectral distribution.

as Wooki says, simply consider the wide variation of bulbs being used in the hobby and compare the statistics of success rate or failure rate. If you are so convince that you can produce a difference then I challenge to to prove it with empirical data of your own. Its all very nice and well to regurgitate information from "...articles outside the hobby.." but until someone from inside this hobby can show differences scientifically then data is considered irrelevant.

People from outside the hobby have been coming to this forum for at least a decade assuming that the data they have from their field of expertise for whatever subject automatically applies to this hobby. Water in a bathtub changes everything. Add salt to that water and things are changed even more - most notably, the relationship between algae and plants, which is completely different from any relationship observed in a petrie dish. We have to be very careful when attempting to determine the relevance.

We, as hobbyists have years of empirical testing of your hypothesis because we too at one point had only data from outside the hobby. Our members have performed side by side tests of bulbs with differing spectral properties and found that there was zero correlation with data from outside the hobby.

You can grow excellent healthy plants with whatever spectral distribution you desire. PAR dete4rmines the growth rate, while CO2, nutrition and tank maintenance determine the plant health. It that simple. Here are plants grown with those garish marine type bulbs in the so-called 10,000K regime (K rating is dubious, but that's what the packaging says). This was no problem whatsoever.

9655594565_72443716a2_c.jpg



Here are plants grown with the so-called 6500K rating. These were absurdly expensive "special plant bulbs"

9633328956_49b5c40fe3_c.jpg



Here are plants grow with bulbs used in office buildings. These were super cheap bulbs which had the so-called 4000K rating and had an orange cast, which I also found gloomy and disturbing.
8394107087_48b5233981_c.jpg




Here I combined all the bulbs but found that using predominantly the orange office bulbs, tempered with daylight and blue bulbs produced my favorite color cast:
8394084393_202488a0e1_c.jpg


I have a PAR meter, so made best efforts to keep PAR within the same range. There was no perceptible differences in plant health and the growth rates were very close. Now, this was not strictly scientific as I had no control tank and did not measure plant dry mass, for example. This was strictly empirical and based on visual observation. Others have carried out similar tests with different bulbs and their results were similar, that they could not determine which spectral property produced better plants. Aesthetics are the main priority, and that's how it should be.

If you've ever seen an ADA gallery, in the past, their bulbs had huge green content and they also produced excellent plants health.

I suggest that the misinformation rests squarely on your shoulders until you provide your own proof. In fact, I'm being unfair because that is a very difficult proposition. We lack control of so many variables in the tank it is doubtful you could actually achieve any pertinent conclusions. What we do know however is that you can pick any bulb spectral properties and obtain very similar results - as long as you are able to grow plants problem free in the first place. The OP should be informed that he can pick any color combination that suits him because we have been growing plants for decades and have not met a bulb spectral property that we could not use successfully, despite claims to the contrary from "...articles outside the hobby.."

Cheers,
 

ian_m

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Commercial hydroponic/greenhouse growers use lights at the pink/red end of the spectrum:
  • This produces the most grams plant mass per Watt input power.
  • Not wasting energy in producing higher energy blue light that makes little difference to plant growth.
  • Not wasting energy in producing any green light which will be simply reflected and not used by the plants.
  • Red end of spectrum LED's are the most efficient in producing highest lumens per Watt.
  • However plants look black (as no green light present), but growth is wonderful.
  • White lights are often present for the workers, so they can see what they are doing when performing maintenance. Apparently working with "missing spectrum" in your working conditions is not nice.

So switch to red/pink LED's fantastic plant growth, low energy consumption. Only problem is plants will look black.
1624006076430.png

Job done. Fantastic plants.
 
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