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Light colour & algae

idris

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Is there any colour light that is less prone to helping algae? Without working things out scientifically, I'm wondering about purely green light (as I think that what's reflected from green leaves... right?)
As much as anything I'm hoping to extend the time I can watch my tank without it causing algae growth.
 

PARAGUAY

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I think its more to do with a balance of your lighting than this light or that light to avoid algae. I always use cheap t5 ( see James C in lighting)tubes and recently budget end nicrew eg LED lights . Seen quite a few examples of more expensive lights with just the same algae issues. Low energy aquariums can have and better for it long photoperiods. Use floating plants is good way to go.Personally go for a pleasing light to your eye.The question about greens and lighting is a technical one. One of our lighting gurus might help
 

ceg4048

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I agree with paraguay. There is no color you can use that will avoid algae. Algae is cause by too much light intensity of any and all colors. If the intensity is low enough then the lights can be on for a long time.

Having said that you can give yourself more room for error with bulbs that do have a high green and yellow content. The old ADA bulbs (the NA bulbs) are very high in green/yellow which made the tank look bright to human eyes but were still had a low PAR output. There were (and probably still are) however, ridiculously expensive.
It's probably better to simply use the old school T8 fluorescent bulbs which doesn't cause much trouble. That's what folks used long ago and rarely suffered as much of these algal blooms. We now have access to LED fixtures which have wattage ratings which seem quite low by comparison - but folks simply do not realize how much more aggressive light intensity is produced for very low wattage.

Cheers,
 

idris

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Are cheap, domestic/ ebay (green / RGB) IP65 LED strips relatively "intense" compared to aquarium specific LEDs. My gut says they ought to be less "intense". But I've no idea how 1hr with something like that would compare with an hour of my iQuatics T5s.
(Throw in a PWM driver from something like an Arduino clone and ... well ... I'm ar least partially out of my depth. I have some components lying around, but no PAR meter.)
 

ceg4048

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Few have any idea, without an objective measuring device, which unit has higher intensity, whether labeled as aquarium specific or otherwise.
Without a PAR meter much of what you see, or much of what you think you see...can easily be an illusion.
More importantly, the advantage of an LED, as long as you spend enough money, is to have a dimmer. If you're a good DIYer then you can cut the wires and assemble it to your own dimmer.

Cheers,
 

akwarium

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Many types of algae can use green light, Rhodophyta en Cyanobacteria have phycobilisomes to catch that part of the spectrum. That is why they don't appear to be green.

If you change your lightning algae usually appear, but with proper maintenance (cleaning the algae away) and care (fertilizing the plants) plants will adapt and make algae disappear again. I light my tanks for 10 - 12 hours a day, because I don't like looking at a dark tank. I have massive outbreaks of algae 7-10 days after setting up a new tank, less light (lower intensity/shorter period) will slow the growth rate of algae down and make it more manageable for sure, but after a few weeks things will improve when plants start growing and take over. In my experience it does not matter if you have low or high light, low or high co2, full EI or lean dosing, as long as you keep the levels consistent, given time plants will beat the algae.
 

ceg4048

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Many types of algae can use green light, Rhodophyta en Cyanobacteria have phycobilisomes to catch that part of the spectrum. That is why they don't appear to be green.
That is true and plants also use green light because they have the same light gathering proteins as algae and cyanobacteria. In fact, green light is used in conjunction with the other wavelengths to deliver those photons deeper which allows these proteins that are below the surface to obtain more light.

The fact that Rhodophyta and Cyanobacteria are capable of using green should NOT be construed to mean that if your light has green this will cause algae.

Cheers,
 

akwarium

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That is true and plants also use green light because they have the same light gathering proteins as algae and cyanobacteria. In fact, green light is used in conjunction with the other wavelengths to deliver those photons deeper which allows these proteins that are below the surface to obtain more light.

The fact that Rhodophyta and Cyanobacteria are capable of using green should NOT be construed to mean that if your light has green this will cause algae.

Cheers,

Well the proteins in plants and algae are not all exactly the same, Chlorophyll A is universal but the other types of chlorophyll are not. Phycobilisomes and the proteins they are made of are restricted to certain types of algae and cyanobacteria. Other chemicals like carotene and xanthophyll are found in both but not in all. So there are some differences, but the end result is very similar. And not relevant for our purposes at all.

it is indeed a widespread misconception that plants will grow better if provided with light in the wavelengths they can absorb best. this is not true, it is only more energy efficient (to some extend)
 

idris

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So more PAR is good for plant growth.
As I can't justify a PAR meter for purchase of a single light, is there any way to find low PAR lighting? (I can build an LED dimmer far more cheaply.) Every light I've seen advertised that mentions PAR seems to be sold on the basis of being good for plant growth, as opposed to good for evening viewing without plant (or algae) growth.
Or am I still missing the point?
 
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dw1305

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Hi all,
Every light I've seen advertised that mentions PAR seems to be sold on the basis of being good for plant growth, as opposed to good for evening viewing without plant (or algae) growth.
You can definitely use a dim light for tank viewing without getting anywhere near light compensation point (LCP) for any photosynthetic organism, plant or algae. Our eyes are really good at adjusting to low light levels and <"subdued room lighting is only 100 to 200 lux">.

cheers Darrel
 

ceg4048

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So more PAR is good for plant growth.
As I can't justify a PAR meter for purchase of a single light, is there any way to find low PAR lighting? (I can build an LED dimmer far more cheaply.) Every light I've seen advertised that mentions PAR seems to be sold on the basis of being good for plant growth, as opposed to good for evening viewing without plant (or algae) growth.
Or am I still missing the point?
It's exactly as Darrel mentions. LCP is a very low energy level and more PAR does not mean "better" growth. It simply causes "faster" growth. There are plenty of tanks using too much PAR where the rate of growth is fast, but the health of the plants is poor. Conversely, there are plenty of tanks lit with low light where the plants are very healthy. People very often confuse "fast" with "better".

Cheers,
 

jaypeecee

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...it is indeed a widespread misconception that plants will grow better if provided with light in the wavelengths they can absorb best. this is not true, it is only more energy efficient (to some extend)...

Hi @akwarium

I'd be very interested in knowing more about this. From what I have read, it seems that action spectra and absorption spectra are closely correlated. And, since action spectra are quantifying photosynthesis activity by measuring oxygen released from a plant, would this not correlate with plant growth? Doesn't the rate of release of oxygen from a plant correlate with plant growth rate? Am I barking up the wrong tree?

If I'm not making myself clear, just say and I'll have another stab at this.

JPC
 

erwin123

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plants can grow pretty fast in the dark though one might not say its 'healthy' growth. I've seen it happen when I did a 72-hour blackout. Fast growth of some stem plants and aerial roots popping out. I've read of some terrestial plants when they are shaded by other plants they try to grow as tall as possible to get sunlight, not sure if thats the explanation for growth during blackout periods as well.

As for the topic light spectra and photosynthesis, I found Bruce Bugbee's youtube videos absolutely fascinating (and of course, I have to credit UKAPS for introducing me to them)
 

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