# Questions regarding RGB Lighting



## Nick72 (25 May 2020)

I've been very impressed with what I've seen of the new RGB lights from both ADA (Solar RGB) and Chihiros (RGB Vivid 2).

They provide far better colour rendition over all previous LEDs I've seen.

As an example I'm very happy with the growth rates I'm achieving with my single Fluval Plant 3.0 (46W) on a 90x45x45 50 US Gallon tank, but the colour rendition is less than optimum, particularly greens which tend to be yellow and washed out.

Would I buy new lights just to improve colour rendition to please my eye.  Yes, I probably would.

So the question.  When setting up previous full spectrum LED lights such as the Fluval Plant 3.0, it's common practice to turn the Blue LEDs down to somewhere between 5%-20% (I have mine on 5%) as Blue LEDs really push algae growth.

The whole point of these new RGB 3 in 1 LEDs is to give you full control over the Red, Green and Blue spectrum the lights push out to deliver such eye pleasing colour reproduction, so do you still need to turn the Blue right down?

If not, why not?


----------



## jaypeecee (25 May 2020)

Hi @Nick72

You have made an interesting observation about blue light in relation to algae growth. May I suggest you take a look at a couple of threads that I started recently - one was today, in fact. Then, we can pursue the points and question you have raised above. Would that be OK? I'm just trying to get an idea of the light spectrum from your Fluval Plant 3.0. Alternatively, perhaps Fluval provide published spectra? Anyway, here are the threads:

https://www.ukaps.org/forum/threads/free-lighting-tool.60842/

https://www.ukaps.org/forum/threads/i-phos-budget-spectrometer.61076/

JPC


----------



## Nick72 (26 May 2020)

Hi @jaypeecee

I had a look at both of your threads, and downloaded Color Picker.

Though I haven't yet taken the RGB of my light.

Here is what Fluval say about the Plant 3.0






I don't really understand the above chart as for example yellow on the chart appears to be at roughly 565nm, which makes sense on the visible spectrum. 

I don't understand why on the key to the left yellow is somewhere between 6500K to 15000K.

Perhaps I don't understand the relationship between nm and K.


----------



## Nick72 (26 May 2020)

OK.  I've read up on nm vs K.

Nm being the visible colour spectrum from 400nm to 750nm.

K being light intensity Kelvin from 1000K to 15000K.

Readings in K are not colour readings but the lights intensity, and a light source of x Kelvin would be made up of of the full spectrum of visible light (nm).

So Fluval putting yellow (or any other colour) on the Kelvin chart is a bit of a nonsense.

Fluval have chosen to put 6. Pink on the Kelvin chart as somewhere above 15000K, where Pink is actually on the high end of the visible light chart below 750nm. 

Even far Red ( near infra red) would likely be below 800nm and nm and K have no corolation and are not convertable.

Please let me know if I've got this wrong.

Can anyone explain the scale Fluval are using indicted as 0, 0.5 and 1 on the y axis of there nm chart and titled 'Spectrum'?


----------



## dw1305 (26 May 2020)

Hi all,





Nick72 said:


> K being light intensity Kelvin from 1000K to 15000K.





Nick72 said:


> I don't understand why on the key to the left yellow is somewhere between 6500K to 15000K.


The K value is the colour of the light emitted by an elemental iron (Fe) body heated to that temperature (in degrees Kelvin). 




I'm not sure what it means on the Fluval graph.

cheers Darrel


----------



## Nick72 (26 May 2020)

dw1305 said:


> Hi all,The K value is the colour of the light emitted by an elemental iron (Fe) body heated to that temperature (in degrees Kelvin).
> 
> 
> 
> ...



So perhaps we are now getting somewhere.

Is it blue on the visible spectrum nm (approx 500nm), or blue on the Kelvin chart (approx 9000K+) that promotes algae growth.

I believe it's Blue on the visible light scale that promotes algae growth.

I don't think going into Blue on the Kelvin scale would make any difference.

To be clear, increased lumen or par would surely increase the chances of algae due to light intensity, but the original post is regarding the dangers of Blue light (eg. Blue on nm scale) to promote algae even at moderate light intensity.


----------



## dw1305 (26 May 2020)

Hi all,
I'm not sure any-one really knows whether specific light wavelengths stimulate some photosynthetic organisms more than others. Because we only have one sun, and it is likely that <"photosynthesis only evolved once">, my guess would be that all photosynthetic organisms can make use of the wavelengths of sunlight pretty effectively. 





Nick72 said:


> Is it blue on the visible spectrum nm (approx 500nm), or blue on the Kelvin chart (approx 9000K+) that promotes algae growth. I believe it's Blue on the visible light scale that promotes algae growth. I don't think going into Blue on the Kelvin scale would make any difference.


They are sort of the same thing, but measured on different scales.  

The <"visible spectrum"> is the range of wavelengths that our <"eyes perceive as colours">. Light is both a wave and particle "photons" , and blue light photons have shorter wavelength, and greater energy, than red light photons etc. 

I'll cc in @jaypeecee back in, spectrophotometry is more his field.





Nick72 said:


> but the original post is regarding the dangers of Blue light (eg. Blue on nm scale) to promote algae even at moderate light intensity.


Because blue light has the shortest wavelength it penetrates furthest into clear water and the marine algae that  live deepest are the <"Red Algae (Rhodophyta)">, which contain phycoerythrin, a red pigment that absorbs blue light.

Black-beard (_Audoinella spp._) and Stagshorn (_Compsopogon_ _coeruleus_ ) algae  are <"both Red Algae">, but I think it this point it would be very easy to add two and two together and get five.  

<"All photosynthetic organisms contain chlorophyll a">, which has absorption peaks in both blue and red light.




_By Chlorophyll_ab_spectra2.PNG: Daniele Pugliesiderivative work: M0tty - This file was derived from:  Chlorophyll ab spectra2.PNG:, CC BY-SA 3.0, __https://commons.wikimedia.org/w/index.php?curid=20509583_

The "Green Algae" (Chlorophytes) contain exactly the same photosynthetic pigments as all the aquarium plants we want to grow and belong to the same clade (<"Chlorobionta" or "Viridiplantae">), so I'd be pretty sure that they don't differ in their light utilisation from the aquarium plants we want to grow.





cheers Darrel


----------



## cbaum86 (26 May 2020)

Nick72 said:


> Here is what Fluval say about the Plant 3.0



The left image you posted from Fluval looks like confusing nonsense to me - not surprised you're not quite sure what's going on.
They're completely different measurement scales and it's weird they've put them on that left side image together.

The graph on the right shows the overall spectrum of the light fitting, but considering you can alter and dim each of the diode colours individually I'm presuming this is at 100%. If you set your own intensity level for each colour you'd have a different spectrum graph - as you note by people setting the blue LEDs to a low %.

The Kelvin, in terms of light fixtures, is the overall hue of the output perceived by your eyes. As Darrel said, the rating is relational to what colour a black body radiator would appear if it were heated to a specific temperature in Kelvin. So heat it to 3000 Kelvin and it would appear a yellow orange, heat it to 8000 Kelvin and it would look more pinky blue.

The measurement of nm is the wavelength of the light, the wavelength represents a specific colour of light. So a blue diode will roughly be around ~460nm and would obviously look really blue to your eye so you may say is around 15,000K. If you added some red diodes they have a wavelength of ~680nm so you'd have a graph with a spike at the blue and red ends, this would look pink/purple and might give you a kelvin of 8,000K.

Whilst you might then say they are linked, and I suppose in a way they are, you could achieve the same kelvin rating with several different spectral curves so you can't have a direct relationship. You can't tell how much of the spectrum is blue because a light has X K rating for example.

But to sum it up, I believe when people say X colour light does this or that for plants, algae etc. they are talking about wavelength.
Kelvin in isolation, apart from how you want your aquarium to look is pretty much marketing so companies can stick another number on the box to sell us something - aesthetics over function.

I believe the Fluval light has white LEDs which have a predominantly blue weighted spectrum because of how LEDs work so you can move the individual blue setting fairly low without affecting the appearance too much. If I were to do that on my Vivid which only has red, blue, green diodes I'd have an orange tank.

🤞I've understood the subject moderately well myself


----------



## Nick72 (26 May 2020)

Thank you all for the above.

I've seen studies on plant (hydroponic - not aquatic) growth under different wave lengths, which suggest that Blue light tends to grow most plants short but full, while Red light tends to grow plants tall but thin.

So  I do believe plants can be effected by wave length.

Anecdotally it's said that Blue light in a planted tank will promote algae growth.   Note that Fluval's default settings for 'Planted' on the Plant 3.0 set the Blue to just 20%.

So if you accept that the blue light on the Fluval Plant series must be used sparingly to prevent algae growth, what implication does that have for setting up a true RGB light such as the ADA Solar or Chihiros Vivid 2?


----------



## Geoffrey Rea (26 May 2020)

Blue light has a short wavelength so will penetrate water more readily.... got ya @dw1305 more blue equals “more intensity”!! (Lost In Translation)





😂 

In all seriousness though the tank above runs 75% white full spectrum LED’s to 25% blue LED’s at 90-100% intensity (200-250 PAR at 30cm depth across most of the footprint) and algae hasn’t been an issue in the last 12 months.


----------



## Nick72 (26 May 2020)

Geoffrey Rea said:


> Blue light has a short wavelength so will penetrate water more readily.... got ya @dw1305 more blue equals “more intensity”!! (Lost In Translation)
> 
> View attachment 149225
> 
> ...



That's interesting.

I can't count the number of articles or videos I've seen where enthusiasts have warned against pushing the blue beyond even 15% when using traditional LED lights.

While anecdotal and not scientific I tend to put faith in practitioners, and my own results suggest I get less algae when I keep the blue above 10% (expectation bias?).

So it's very interesting that you can run 25% blue LEDs at near full power without algae issues.

That's leaves me confused.

(I also just noted in your previous post that you say the white lights in the Fluval Plant 3.0 are also emitting heavily in the blue spectrum - I didn't know this. )


----------



## dw1305 (26 May 2020)

Hi all, 





Geoffrey Rea said:


> In all seriousness though the tank above runs 75% white full spectrum LED’s to 25% blue LED’s at 90-100% intensity (200-250 PAR at 30cm depth across most of the footprint) and algae hasn’t been an issue in the last 12 months.


My guess would be that the wavelength of light isn't a major factor in algae growth. <"Taxonomically algae isn't a very useful term">, so I just think of all photosynthetic organisms as "_plants_",  just some are the "_plants you want_" and some are "_plants you don't want_". I'm going to start by making conditions suitable for plant growth, I'm not going to worry too much about what those plants are.  





Geoffrey Rea said:


> Blue light has a short wavelength so will penetrate water more readily.....got ya @dw1305 more blue equals “more intensity”!!


Yes, it is back to the same thing expressed in different ways.  From <"Photon energies....">






Nick72 said:


> I've seen studies on plant (hydroponic - not aquatic) growth under different wave lengths, which suggest that Blue light tends to grow most plants short but full, while Red light tends to grow plants tall but thin.
> 
> So I do believe plants can be effected by wave length.


Yes, that is right. If you look on hydroponic websites there are various blue and red LED arrays that you can use to grow "Tomatoes"* with differing growth anatomy, dependent upon whether you want your plant as a leaf vegetable or a flowering one.  Even though "relative quantum efficiency (RQE) curves" show the highest efficiency is for red/orange wavelengths you need to add in some blue light to get normal growth.

*Other plants may be available

cheers Darrel


----------



## Geoffrey Rea (26 May 2020)

Nick72 said:


> I can't count the number of articles or videos I've seen where enthusiasts have warned against pushing the blue beyond even 15% when using traditional LED lights.






^^^ From Practical Fishkeeping circa 2008

https://www.practicalfishkeeping.co.uk/features/problem-solver-nuisance-algae/

They never cite anything when making claims like the above. The other is using lower K lighting on marine won’t pack the same punch, a consequence not a cause.




dw1305 said:


> I'm not sure any-one really knows whether specific light wavelengths stimulate some photosynthetic organisms more than others. Because we only have one sun, and it is likely that <"photosynthesis only evolved once">, my guess would be that all photosynthetic organisms can make use of the wavelengths of sunlight pretty effectively.



I agree, it also would be an evolutionary disadvantage to be too specific.

Do have to wonder if this simply all began with someone using marine lighting, heavy on the blue and very high PAR, on a freshwater setup and it turned their tank into an algae farm... Then they drew the conclusion that it must be blue light causing this and the idea rolled out from there.



Nick72 said:


> While anecdotal and not scientific I tend to put faith in practitioners, and my own results suggest I get less algae when I keep the blue above 10% (expectation bias?).
> 
> So it's very interesting that you can run 25% blue LEDs at near full power without algae issues.



It’ll be more than 25%. A quarter of the LED’s in use are blue, there’s also the blue emitted from the other 75% of white LED’s on top.

Much like your experience I find the Anubias and Bucephalandra are much healthier with more blue in the mix and cope with higher intensity lighting. Can’t explain why though.


----------



## jaypeecee (26 May 2020)

cbaum86 said:


> But to sum it up, I believe when people say X colour light does this or that for plants, algae etc. they are talking about wavelength.



Hi @cbaum86 

Spot on! Of course, it may not be a single wavelength but a band or collection of discrete wavelengths.

With reference to colour temperature in degrees Kelvin, I quite like the material on Wikipedia. I think the animation showing black-body radiance vs. wavelength and Temperature/Source Table are pretty good. This is what I'm talking about:

https://en.wikipedia.org/wiki/Color_temperature

JPC


----------



## jaypeecee (26 May 2020)

Hi Folks,

Referring to the Wikipedia link in my previous post, I promise that I didn't contribute the bit that says "In freshwater aquaria, color temperature is generally of concern only for producing a more attractive display.[citation needed] Lights tend to be designed to produce an attractive spectrum, sometimes with secondary attention paid to keeping the plants in the aquaria alive". But, in my opinion, it's making a good point. I might replace the word 'alive' with 'healthy' and add something about algae and cyanobacteria.

JPC


----------



## sparkyweasel (26 May 2020)

Geoffrey Rea said:


> Do have to wonder if this simply all began with someone using marine lighting, heavy on the blue and very high PAR, on a freshwater setup and it turned their tank into an algae farm... Then they drew the conclusion that it must be blue light causing this and the idea rolled out from there.


That sounds likely. Like a lot of the strange ways of 'cycling' a tank, which seem to have been 'borrowed' from marine use, even though the situation is quite different.


----------



## sparkyweasel (26 May 2020)

Geoffrey Rea said:


> I agree, it also would be an evolutionary disadvantage to be too specific.


It would. If anything has evolved to need more specific light or other conditions it will be our delicate plants, some of which are found in a particular niche. Many kinds of algae manage to thrive just about anywhere, and 'algae' as a group includes something that can take advatage of just about any conditions except extremely dry.
I don't believe we can provide lighting under which 'higher' plants will thrive but algae cannot survive. If lighting manufacturers want to claim that, I would like to see some actual evidence.
I think the best we can do is to try to get the plants thriving so that they can outcompete the algae, - aim for conditions that are 'good for plants', not 'bad for algae'.


----------



## jaypeecee (26 May 2020)

Nick72 said:


> The whole point of these new RGB 3 in 1 LEDs is to give you full control over the Red, Green and Blue spectrum the lights push out to deliver such eye pleasing colour reproduction, so do you still need to turn the Blue right down?
> 
> If not, why not?


 
Hi @Nick72 

It would make sense to me that you may need to carefully consider the amount of blue light entering a tank. That's because white LEDs start out life as blue LEDs. This blue light passes through a phosphor inside the body of the LED. The phosphor fluoresces re-emitting white light composed of blue, green and red light in this order of intensity. To this light is then added more blue from the blue emitter in the RGB LED. And this RGB LED also emits green and red light, of course. But, the combination of a white LED and an RGB LED seems to result in more blue light than either green or red light. I'll see if I can dig out some typical spectra to further illustrate the points that I'm trying to communicate in words. But, that's for tomorrow.

JPC


----------



## Geoffrey Rea (27 May 2020)

sparkyweasel said:


> It would. If anything has evolved to need more specific light or other conditions it will be our delicate plants, some of which are found in a particular niche.



I think in terms of process. We prevent our plants (weeds really) from reaching the surface constantly. We’re imposing a survival strategy for the plant then expect health. Algae appears alongside organic breakdown... it’s x y or z that caused it. Human beings love assigning causation in place of correlation because it helps underpin a belief structure. Much like nutrition, spectrum is a stick to measure something. It tells you nothing about process. Laugh at it, love it, hate it... the matter becomes how you adequately test it. It’s very difficult to test a process reliably.





dw1305 said:


> If you look on hydroponic websites there are various blue and red LED arrays that you can use to grow "Tomatoes"* with differing growth anatomy, dependent upon whether you want your plant as a leaf vegetable or a flowering one.



Could be off the mark here but to include @dw1305 comments that are probably more useful, I see the difference in growth anatomy to reflect available photon bombardment/spectrum to the plant throughout a season. If varied spectrum does play a role, it will be a signature to a plant as light from the sun passes through the atmosphere at varying angles. Contemporary species of ‘Tomato’ plants are seasonal and grow where light quality will change throughout the season. Would surmise (without any evidence) genes will loosely dictate what a plant will react to according to seasonal growth period in theory and should adapt to conditions. Temperature alone certainly hasn’t fully explained germination rates in my experience with terrestrial species. What about the affect on microbial life and it’s part in the process for instance? Symbiotic life systems seem to have been forgotten here.

Why would applying one perfect spectrum throughout a season replicate the plants natural process? You could argue that equatorial regions where tropical aquatic plants hail from enjoy consistency. But light intensity will change with the rains found in tropical regions. Increased humic conditions will change the amount of organic material in the water of tropical water courses/bodies affecting light penetration.

Growing plants in zero gravity... now there’s where things get interesting.


----------



## sparkyweasel (27 May 2020)

Geoffrey Rea said:


> Why would applying one perfect spectrum throughout a season replicate the plants natural process? You could argue that equatorial regions where tropical aquatic plants hail from enjoy consistency. But light intensity will change with the rains found in tropical regions. Increased humic conditions will change the amount of organic material in the water of tropical water courses/bodies affecting light penetration.


Also, many of our 'tropical aquarium plants' are not from equatorial regions. Especially some of the old-established favourites; we got Vallis from Italy, Cabomba and Sagittaria from USA and I'm sure there are lots more when I have time to check.


----------



## Geoffrey Rea (27 May 2020)

sparkyweasel said:


> Also, many of our 'tropical aquarium plants' are not from equatorial regions. Especially some of the old-established favourites; we got Vallis from Italy, Cabomba and Sagittaria from USA and I'm sure there are lots more when I have time to check.



Very good point @sparkyweasel


----------



## Nick72 (27 May 2020)

Thank you all.

So the consensus:


Blue light should have no specific impact on algae growth in a freshwater planted aquarium.
Increasing blue light (or any other colour) settings will naturally increase overall light intensity which may increase algae growth.
Blue light has a shorter wave length than other colours, so a 10% increase in blue light may have a bigger impact on overall light intensity at substrate than a 10% increase in an alternative wave length.

  I still wonder why of the three default settings offered by Fluval for the Plant 3.0, two have blue light set to zero, and Planted has blue light set to 20%.  All other wave lengths are set between 75-100% across all defaults.

Is this purely because they believe these settings provide the most natural look to the human eye, or is there another reason they are being so lean on blue?




jaypeecee said:


> Hi @Nick72
> 
> *It would make sense to me that you may need to carefully consider the amount of blue light entering a tank*. That's because white LEDs start out life as blue LEDs. This blue light passes through a phosphor inside the body of the LED. The phosphor fluoresces re-emitting white light composed of blue, green and red light in this order of intensity. To this light is then added more blue from the blue emitter in the RGB LED. And this RGB LED also emits green and red light, of course. But, the combination of a white LED and an RGB LED seems to result in more blue light than either green or red light. I'll see if I can dig out some typical spectra to further illustrate the points that I'm trying to communicate in words. But, that's for tomorrow.
> 
> JPC



@jaypeecee  - You say this because adding more blue light will look unnatural? Or for another reason?


----------



## Geoffrey Rea (27 May 2020)

Dennis Wong’s site is a good port of call for a bit more reading on lighting spectrum and mixing:

https://www.advancedplantedtank.com/blogs/beginners-planted-tank-101/best_light_spectrum



Nick72 said:


> I still wonder why of the three default settings offered by Fluval for the Plant 3.0, two have blue light set to zero, and Planted has blue light set to 20%. All other wave lengths are set between 75-100% across all defaults.



Best guess @Nick72 would be unless you have plants under their unit, the additional blue would just add unnecessary deeper penetrating short wave blue light to the bottom of the tank. Diatoms would appreciate it but if no plants are using that light to photosynthesise, then algae would potentially be an issue in a fish only setup.

People may buy the Plant 3.0 because they enjoy the colour rendition it gives their fish without necessarily intending to grow plants.


----------



## jaypeecee (27 May 2020)

Nick72 said:


> @jaypeecee - You say this because adding more blue light will look unnatural? Or for another reason?



Hi @Nick72 

I say it not for aesthetic reasons but because excess blue light could encourage algae. I'm also suggesting that there may be an excess of blue light for the reasons I tried to explain above. BTW, I don't quite understand your first two bullet points in post #22 above. They appear to contradict each other. But it may just be my interpretation.

@Geoffrey Rea has raised a very important point about the depth of light penetration in water. At depths up to 90cm, the reduction in both blue and green is negligible but _reduction_ in red at 660nm is 75% (i.e. down to 25%). And, at 60cm, red would reduce to 50%. Therefore, the light being emitted from the lighting fixture needs to take this into account. My hunch is that many manufacturers of aquarium lighting do not consider these details.

JPC


----------



## Nick72 (27 May 2020)

Geoffrey Rea said:


> .......
> Best guess @Nick72 would be unless you have plants under their unit, the additional blue would just add unnecessary deeper penetrating short wave blue light to the bottom of the tank. Diatoms would appreciate it but if no plants are using that light to photosynthesise, then algae would potentially be an issue in a fish only setup.
> ......





jaypeecee said:


> Hi @Nick72
> 
> I say it not for aesthetic reasons but because excess blue light could encourage algae. I'm also suggesting that there may be an excess of blue light for the reasons I tried to explain above.
> 
> ....JPC




OK.  From your early posts and having read the article by Dennis Wong I was coming around to the concept that Blue light has no appreciable effect on algae beyond that light of any spectrum at too high an intensity can contribute.

In fact I've just raised my blue light to 15% and taken 25% off a combination of white lights to compensate for overall intensity.

But in both of your posts above you are now suggesting that excess blue light can contribute to algae and diatoms.  

It feels like a mixed message to be honest.

I was just considering, if blue light does not stimulate algae growth, why I might not increase my blue light to something much higher, say 50%.

I think that might help colour rendition, where my greens are yellow-ish, would not additional blue create a better green.

But your last two comments have given me pause.


----------



## Nick72 (27 May 2020)

jaypeecee said:


> ....BTW, I don't quite understand your first two bullet points in post #22 above. They appear to contradict each other. But it may just be my interpretation......




Point one states that Blue light is no more of an algae stimulator than any other spectrum.

Point two states increasing any light spectrum to the point of excess intensity will stimulate algae growth.

I could probably have phrased it better the first time, but no I don't believe they contradict.


----------



## jaypeecee (27 May 2020)

Hi @Nick72 

I'm not sure how to clarify things any further. Perhaps I'm losing my written communication skills. I'll re-visit this thread at a later stage to see if there's anything we can do. It's a complex subject and being able to communicate with words would help but that's not practical.

JPC


----------



## Nick72 (27 May 2020)

jaypeecee said:


> Hi @Nick72
> 
> I'm not sure how to clarify things any further. Perhaps I'm losing my written communication skills. I'll re-visit this thread at a later stage to see if there's anything we can do. It's a complex subject and being able to communicate with words would help but that's not practical.
> 
> JPC




Sorry @jaypeecee - I'm not trying to be difficult.

I've just read this thread again from top to bottom.

Actually you never stated that Blue light does not cause algae, if anything you say that it can.  So sorry if I misrepresented you.

I also do completely take your point that white LEDs are biased towards the blue spectrum.

But until the last couple of posts which I highlighted (yours included) every previous post had stated that Blue light categorically does not promote algae growth.

So those last couple of posts threw me.

I sincerely appreciate everyone's input, just wish the answer was more clear cut.


----------



## jaypeecee (27 May 2020)

Hi @Nick72

No problem, my friend. Now that we've cleared up any confusion/misunderstanding, we can pursue this further if you wish.

JPC


----------



## jaypeecee (28 May 2020)

Hi @Nick72 & Everyone,

There's one other thing that I failed to mention about blue light and that is - it shrinks plants!  You may want to look at the following in which Dr Bruce Bugbee talks more about this. I don't know how I managed to forget this but so be it. Here's the video:



I have referenced this video before on UKAPS.

Dr Bugbee generally refers to terrestrial plants. I don't know to what extent his statements apply to aquatic plants.

JPC


----------



## cbaum86 (29 May 2020)

Hi @jaypeecee

Sorry, maybe I missed something in one of your earlier comments or links. I know you don't say that blue light causes algae you state it could, but I'd be interested to know why.

Is it something to do with the actual wavelengths in the blue part of the spectrum have an impact on some particular biology which stimulates the algae grow more than it would with another colour?
Is it because the blue light has the ability to penetrate deeper into the aquarium. So if you had a shallow tank with red LEDs is there just as much impact on algae growth as a deeper tank with blue LEDs for example?
Is it that blue light in itself does not cause algae but more the fact there is a chance of excess blue light in a lot of fixtures because of the combination of white and blue LEDs. So any excess of light will cause algae, it's just in the majority of cases this happens to be blue.
Something else or a combination?
Also, is all algae the same in terms of light reaction? I know Darrel made a comment earlier about potential difference between red and green algae.

Apologies, I may have butchered some of the understanding on the topic but I like to try understand things a little better and try to ask the right questions so I can at least make what I think is an informed opinion on the subject.

Thanks,
Chris


----------



## jaypeecee (29 May 2020)

Hi @cbaum86


cbaum86 said:


> Sorry, maybe I missed something in one of your earlier comments or links. I know you don't say that blue light causes algae you state it could, but I'd be interested to know why.
> 
> Is it that blue light in itself does not cause algae but more the fact there is a chance of excess blue light in a lot of fixtures because of the combination of white and blue LEDs. So any excess of light will cause algae, it's just in the majority of cases this happens to be blue.
> 
> Also, is all algae the same in terms of light reaction? I know Darrel made a comment earlier about potential difference between red and green algae.



Hi Chris,

Firstly, I am just someone who has read extensively on the subject of plant lighting. A lot of the time, that means turning to horticulture where there is the commercial need to use every photon of light efficiently. And my understanding is that Dr Bugbee (above) has done a lot of work for NASA to enable crops to be grown on the ISS. Unfortunately, there doesn't appear to be much similar work taking place on aquatic plants. I guess if the likes of Tropica and Aquafleur were growing submerged aquatic plants, things might be different. But, it would appear that most plants destined for our tanks are grown emersed. In summary, I consider myself to be an enthusiastic amateur in this field but I'm no expert.

Anyway, in answer to your question, you will see that I have highlighted your post (in blue!) the option that I believe to be the case. I would, however, prefer to say that 'any excess of light _may_ cause algae'. If you haven't yet visited Dennis Wong's web site, here's a good starting point:

https://www.advancedplantedtank.com/blogs/light-3pillars

JPC


----------



## cbaum86 (29 May 2020)

Thanks @jaypeecee.

I like to think I'm gaining a better understanding of these things and in a debate it's always helpful to use my own informed opinion with some understanding rather than just say "because so-and-so on X forum said so".  Much more convincing an argument to be able to say "I think X because of Y and this group of so-and-sos have similar experience/thoughts". Although like you say, I find there is a lot of information we have to imply to the aquatic side based on terrestrial info/studies.

I've previously seen some other videos from Dr Bugbee that were very interesting but I'm always cautious to correlate that directly to our aquatic plants - still it hasn't hurt me doing so so far.



jaypeecee said:


> I would, however, prefer to say that 'any excess of light _may_ cause algae'.


A very good point. Need to be careful with the wording.



jaypeecee said:


> If you haven't yet visited Dennis Wong's web site, here's a good starting point:


I've been referencing the site for the past year or 2 now, great resource. Struggling to find everything I remember reading on the new layout though.

Cheers!


----------



## dw1305 (29 May 2020)

Hi all,


cbaum86 said:


> I know Darrel made a comment earlier about potential difference between red and green algae.


The Green Algae  (Chlorophyta) are the basal group to all the green plants (together they form the clade <Chlorobionta or <"Viridiplantae">) and <"share a  common ancestor">, from which they all inherited the same <"basic physiology and photosystems">.






In terms of photosynthetic pigments, and light interception, there are only very minor differences between any of the members Viridiplantae clade. If you like what is "_sauce for the goose is sauce for the gander_".

<"Cyanobacteria, Red Algae (Rhodophyta) and Diatoms"> are much more distantly related to all the green plants.

cheers Darrel


----------



## jaypeecee (29 May 2020)

Hi @dw1305 / Darrel

The link immediately above (Cyano...Diatoms) doesn't appear to be working for me. I take it that it works for you?

JPC


----------



## dw1305 (29 May 2020)

Hi all,





jaypeecee said:


> The link immediately above (Cyano...Diatoms) doesn't appear to be working for me.


No, it looks like I failed to link <"in the page">.





cheers Darrel


----------



## jaypeecee (29 May 2020)

Hi @dw1305 (Darrel)

Thanks a lot. That's a useful tree and link.

Ta very much.

JPC


----------

