Is Algae worse with LED lighting?

[Barbara Turner]

I was chatting to the owner of my local fish shop about planted tanks and Algae and he said that
"Now we sell LED lighting we have far more customers having problems with Algae"

My first question is
Do we think that this is correct?
I’m sure we still had algae problems but are they fewer?

My initial thought was that this is just due to the fact that most LED units are far more powerful than the fluorescent units he previously sold but looking around most of the LED lights for sale are less than 30w so I’m not convinced this is true.

Looking at the light spectrum of a fluorescent bulb, it produced far more UV light than LED’s do, (even if that wasn’t much). I also understand that UV is also harmful to plants but even more so to Algae.

Reading up on recent research plants can often adapt to UV lights and survive, it just made me wonder if we should add very low levels of UV light to our fish tanks.

 

[Tim Harrison]

Could be possible, although I'm not sure about the photo response of algae vs higher plants, and I happen to be one of the minority that believes spectrum matters.
However, I think that it perhaps has more to do with your initial thought. Every LED light is different, whereas the output of fluorescent tubes is fairly consistant.
With LEDs there isn't really any rule that can be applied across the board and it's this lack of consistency that could easily lead to algal issues.

I've used a few different types of LED unit and know from personal experience how difficult it can be to get the intensity right, especially if you are unfamiliar with the unit.
My Radion XR15 FW, has a UV LED in the array, a legacy from the manufacturers reef origins, and regardless, if the intensity is too high algae starts creeping in from the edges.
That's is why I always recommend buying a LED light with a dimmer or a light that can at least be retrofitted with one.

In addition, at the end of the day there is still no substitute for good tank husbandry, and effective implementation of CO2 through good flow and distribution. As well as a good fertz regime of course. It's these things that folk often get wrong.
And, I'm sure that your LFS owner is very knowledgable, but IME these guys are more likely to lead hobbyists astray.

 

[BubblingUnder]

the output of fluorescent tubes is fairly consistent.

Not sure this is true over time. I used to run 2 fluorescent tubes on my aquarium & had to swap them over carefully to maintain roughly the same light levels. If I didn't I noticed more algae appeared as the amount of available light fluctuated. Perhaps LED's suffer much less degradation over time.

This article describes the light reduction on T8 fluorescent tubes over time but I can't vouch for the science.
https://www.lrc.rpi.edu/programs/NLPIP/lightingAnswers/t8/06-t8-lumen-maintenance.asp

 

[zozo]

Since i'm back into the hobby a few years now with multiple tank syndrom. I've builded several diy led fixtures with different types of leds, SMD, COB type leds.

I absolutely can't say anything about spectrum, since most scientists in the field are yet not sure if and how the plant uses the complete spectral range of light available. So it could very well be that plant sp. independendly biologicaly developed to use available light differently and maybe have a preference. Take for example a fern that prefers to grow in shaded spots. It evolved to grow in the shades and we know shaded light has more Blue wavelenght in its spectrum. Even if we don't know i can imagine a fern might be happier with less intensity and more blue, compaired to its flowering sun loving counterpart that is happier with a lot more intensity and a tad more red. If that is so, than algae probably has simmular prefernces.. It might be true for any photosythesizing organism, biologists have found evidence of photosythesizing bacteria in nature prefering the red spectrum.

https://www.futurity.org/far-red-light-bacteria-751962/

If algae growth is worse with led lighting in general imho more likely more comes down to the big difference between the way led light is distributed compaired to a tube light.

A led is simply much more intense in usefull light than a tube because it directs all light straight down in a rather narrow angle between 60° and 120° depending on the type of led. A tubelight scatters the light in a 360° and a big part needs to be reflected down again. Not only loosing intensity but the reflector likely also changes the spectrum. Anyway, a led gives a lot more usefull bundled light without much spectral loss and if you want to spread it you need multiple sources in aray. Than even if our eyes do not percieve it as more intense, because if you look straight into it you are blinded to much by both telling you zip, than all you have is look at the invironment and also not realy see the difference in intensity. But a 1000 lumen led aray produces at least 50% more usefull light with greater intensity than a 1000 lumen tubelight.

Than a dimmer indeed aint redundand luxery.. More likely a must have..

 

[Tim Harrison]

the output of fluorescent tubes is fairly consistant.

Not sure this is true over time.

Okay, maybe I should have qualified that, by writing...relatively consistant by comparison...

This article describes the light reduction on T8 fluorescent tubes over time but I can't vouch for the science.

We've had a few discussions on this topic over the years and I think the consensus was that it's largely mumbo jumbo concocted by manufacturers to get us to buy more tubes, for instance https://www.ukaps.org/forum/threads/when-to-change-bulbs.34744/#post-371449

 

[mort]

I think a lot of this has nothing to do with led but more to do with the modern world. I ran a lfs and lots of people who kept plants had no real problems with algae until you actually saw a picture of their tank. Bba was nearly always constant and I think they just thought it was a normal part of the tank. It's only today with the way infomation is easily available that people actually know different.
So for me the rise of led has coincided with the rise in forums and showing off what we have.

But just to contradict myself a little there has been a link with certain led colours promoting algae in marine tank, especially green and red. I'm not convinced these are any worse than a full spectrum light source but it's easy to just turn them down which is actually a benefit.

 

[Simon Cole]

I am not sure that LED's do not suffer from considerable "spectral loss". The website below states: "LEDs emit light in a very small band of wavelengths, emitting light of a colour characteristic of the energy band gap of the semiconductor material used to make the LED". Source: http://www.lllwww.co.uk/about_led.html.
When I researched my LED chips, I found that the waveband was incredibly narrow. I would need specialist scientific equipment to actually measure an LED array, but overall the results are unlikely to be much different from that hypothetical argument. When we consider that fluorescent tubes have multiple excited electron states - they have considerably more distributed wavelength banding. Now the interesting part comes when we consider the wavelengths preferred by algae as opposed to plants, and their ability to utilise that energy. I would say Barbara, that like Tim, I also happen to be one of the minority that believes spectrum matters. That is to say, I would prefer any technology that gives me a broader band of wavelengths that is engineered towards plant growth and not algae.
I am not sure that semiconductor technology is sufficiently advanced enough to give similar flexibility in design-engineering choice.
I have not reviewed all the scientific literature, but if somebody knows more that would be really interesting.

 

[zozo]

@Simon Cole

http://scapefu.com/lighting-planted-aquarium-cara-wade/

https://www.facebook.com/cara.wade.9

 

[dw1305]

Hi all,

Now the interesting part comes when we consider the wavelengths preferred by algae as opposed to plants

The marine red algae (<"Rhodophyta">) are often found towards the lower end of the photic zone, where the only wavelengths of light that haven't been scattered are the at the blue end of the spectrum. They have different photosynthetic pigments, including phycoerythrin.

But there isn't really a difference for the "green algae" (<"Chlorophyta">), they share the same photosystems (chlorophylls a & b etc.) as all the vascular plants (mosses, ferns & flowering plants), because they have a common ancestor (they all belong to the clade <"Chlorobionta"> or <"Viridiplantae">).

cheers Darrel

 

[Tim Harrison]

At first it appears that LED lighting can be a bit of a minefield. But I reckon it's fairly straight forward really. Choose a light that you like the colour rendition off; the visual spectrum is the same as the photosynthetically active spectrum give or take a few nm (400-700nm) so it's a good bet it'll be perfectly adequate for growing plants. Make sure it's dimmable and has the intensity to grow the plants you want and away you go.

As for LEDs having a narrow band of wavelengths; both the visual and photosynthetically active spectrum are narrow, and only a very small part of the electromagnetic spectrum . And further, many of the new generation of LEDs units are RGB which I think gives better colour rendition and perhaps helps to bring out the reds in some plants and maybe also helps to encourage the compact growth forms that aquascapers find attractive; photomorphogenesis

As for the OP... is the quality of LED light more likely to encourage algae than say T5s? Darrel's post above would suggest not. Either way it shouldn't really make that much difference in a well maintained and balanced aquarium.

 

[zozo]

What i understood from the theory how White light is created with LED is.. All crud leds are in fact only emitting light in the blue spectrum.. Than they need to be coated with Phosphor to emit white light.

Since it a natural sourced product there is a huge difference in the used phosphor contents, pure phosphor is white, but containing contaminents it can have a range of colors yellow, green and red, in different color intensities one can look orange and the other red and both are still phosphor. Thus it kinda depends on the manufacturers phosphor source what kind of white their led emits. The phospor filters parts of the blue into a mixture of RGB.

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

As i experienced myself, buying leds with a 10000K (cool white) specefication and looking at it it was more emitting pink light than blue. And a 10000K from another manufacturer looked completely different again without any vissible reds at all. I guess the manufacturer needs to make consesions regarding the purity of their phospor to create a light in the so called K standard we use in the trade.

Than it seems, depending on techniques used applying this coating it can result in sone spectrum differences.

 

[Tim Harrison]

I suppose that could really answer the OP, in that LEDs from different manufacturers are not all the same. If you follow the logic, it's unlikely to be LEDs that cause algae since surely they are all too different to have that one thing in common...a quality or spectrum of light that causes algae ?

 

[zozo]

I suppose that could really answer the OP, in that LEDs from different manufacturers are not all the same. If you follow the logic, it's unlikely to be LEDs that cause algae since surely they are all too different to have that one thing in common...a quality or spectrum of light that causes algae ?

That's indeed also the logic i followed.. As said builded several led fixtures over the years and the specs given by the wholesalers are 2700K, 6500K and 10000K, very few times encountered 8000K. But in general the first 3 are most common. Or they give no K at all and say Warm, natural or cool white. Than if you compare them and clearly see one different in color than the other but have been given the same specs. Than it's obvious that or they do not measure it or each development lab has it's own color chart to determine it. I wouldn't know, how or what. It kind a seems a giving a K number gives a more professional appearance to the customer, rather than only Warm. Than it's choosen by the seller to target a certain customer.

But in the end you do not know what you realy get. I doubt there is anybody who knows what 6500K realy stands for and how it should look. How do you actualy determine a light color?

Than if you combine the 3 given K colors you mix it completely up and gives the ability to slightly change it to own preference.

Not to forget and seldomly given in the specs, some leds change slightly in color output when dimmed (receiving less voltage) or when getting warmer. Than take for example invironmental temperatures fluctuate according to the seasons with rather dynamic cooling propperties for the leds. With an average 20° winter and up to 35° summer temps. Can give you a dynamic spectrum all through the year..

There is just to much we do not know and maybe don't notice with the nacked eye.

I also do not know, than i have to guess and i think the LED relatively gives more PPFD per sqaure than any other light with the same output specs. Because it's much narrower beam angle. And that imho is more likely the reason why many people experience an algae outbreak after switching to led..

 

[Tim Harrison]

I also do not know, than i have to guess and i think the LED relatively gives more PPFD per sqaure than any other light with the same output specs. Because it's much narrower beam angle. And that imho is more likely the reason why many people experience an algae outbreak after switching to led..

That's what I think too

 

[Simon Cole]

Thanks for the info Darrel. I would feel a lot more confident choosing an LED array after reading these posts, so it is really helpful stuff.
There are a few manufacturers that include lenses over the LEDs to widen the beam angle.

 

[zozo]

There are a few manufacturers that include lenses over the LEDs to widen the beam angle.

That's because not all lenses are suitable, a lot give a prims effect bellow the water level inside or outside the aqaurium.

Few years back searching info for my first led buildibg experiments i stumbled uppon a forum thread with pictures of someone who made use of lenses. Creating several rainbow colored beams in the water. After removing the lenses it was normal again. Can't seem to find that thread back, i have forgoten the proper search query i guess.

 

[Simon Cole]

Cheers Marcel, I didn't know that.

 

[Tim Harrison]

The Radion I mentioned previously has a lens over it. There is/was a choice between 80° and 120° spread, it comes with the latter as standard now. However, the lens still doesn't prevent hot spots; higher light areas where algae is likely to appear.
It also creates a split spectrum, or rainbow effect, which I actually quite like tho'; that and glitter lines, which are spectacular.

Mr. Teapot's Green Pekoe Pond showing the rainbow effect created by the Radion XR15 FW lens https://www.ukaps.org/forum/threads/green-pekoe-pond-40-litres.27575/page-14#post-390344...

Another of Mr. Teapots images from the same journal showing the Radions LED puck, with lens...

 

[dw1305]

Hi all,

is the quality of LED light more likely to encourage algae than say T5s? Darrel's post above would suggest not.

That would be my guess. It can't really make any difference for the green algae, and all the other photosynthetic organisms have evolved to use sunlight, and photosynthesis has probably <"only evolved once"> (but at least <"3,500,000,000 years ago">).

Because of the different photosynthetic pigments in diatoms (chlorophyll c, fucoxanthin), cyanobacteria (phycocyanins, phycoerythrins) and red algae (phycoerythrins) they might use slightly different wavelengths of light, but you are still back to having all evolved in sunlight, the spectra of which is pretty constant.

If you found a planet, with photosynthetic organisms, that orbited a star that emitted light at different wavelengths I would bet (a pretty safe bet) that the pigments would differ, but would have evolved to maximise energy interception at the appropriate wavelengths. We think of visible light as different from all the other electromagnetic wavelengths (390 to 700 nm), but it isn't, we've just evolved to "see" it.

If I was to guess that any of these groups are preferentially favoured by different wavelengths of light, when compared to the Viridiplantae, my suggestion would be the Red Algae (including BBA and Staghorn). If you find sub-tidal red algae in deep rock pools on the shore they are often "bleached", presumably by the extra energy of the sunlight when it isn't attenuated by a reasonable depth of water.

Because the freshwater "pest" red algae (Compsopogon & Audouinella spp.) aren't red that makes me think that they have a lot of carotenoid pigments, that mask the photosynthetic pigments and give them some form of "sun-cream".

cheers Darrel

 

[Oldguy]

I am of the view that spectrum matters, though plants do grow under less than ideal conditions.

When using fluorescent tubes I used cold white and glowlux. It gave decent colour rendering & plant growth.

When I moved over to LED's (the luminair required re-tubing and one of the ballasts was starting to corrode and most importantly for me was the price of LEDs were falling) I chose units with multiple colours as well as 'white'. In addition I added other LEDs with a cone shaped output as spotlights. These are easy to change and are currently a mix of white and red/blue hydroponic lights. None can be dimmed (to my knowledge) but each bank are on timers. There can be a spectral shift as voltage is lowered on LEDs but whether it is significant is doubtful.

I view some algae in a tank as natural (try keeping the spores out, they are in the air we breath) but try and run conditions that favour vascular plants

Views from lfs, ask the the same question in ten different shops and you will get at least twelve different answers.

Light intensity, CO2 and fertzs and striking a balance is key.