How important is light cycle?

[Deleted member 149562]

This is what I use on my aquariums.....the 8 inch version (they do come in longer sizes too)


https://www.amazon.co.uk/dp/B07G32T1N6/?tag=

 

[Myraan]

Green light is not just for aesthetics. Green is very much in the spectrum used by plants and will promote growth, possibly as much as red light. Look outside at all the green around in our world. That green light would be reflected in most fish's natural environment as well.

The only reason reflected green light is naturally present is because it is not absorbed by the plant pigments because it is not used. If our light source lacks green I would assume the plants in our tanks would look grey or even black. So yes, in that sense it is for aesthetics. Whether ignoring this aspect of aesthetics would impact the well-being of our fish is a whole other matter.

 

[xxBarneyxx]

This is what I use on my aquariums.....the 8 inch version (they do come in longer sizes too)


https://www.amazon.co.uk/dp/B07G32T1N6/?tag=

Sorry to take this completely off topic but are you actually growing plants with these lights?

I was looking at them the other day for a couple of ideas I had but didn't think they looked overly good.

 

[noobfish]

The only reason reflected green light is naturally present is because it is not absorbed by the plant pigments because it is not used. If our light source lacks green I would assume the plants in our tanks would look grey or even black. So yes, in that sense it is for aesthetics. Whether ignoring this aspect of aesthetics would impact the well-being of our fish is a whole other matter.

Green light is present in the white light as well, as is the entire spectrum. While I agree that the color we see is what color is reflected by an object, that does not mean that none of that color is absorbed (or used) by an object. I've read quite a few articles by planted aquarists that have experimented with light spectrum and more than one has had more plant growth with green than without. What their controls were and how scientific their studies were I can not say, but I myself have seen significant plant growth with my current program.

 

[Myraan]

Just want to clarify so I found this pic on bing. I think @noobfish knows this, this is just to help people realise the graph I found is a different thing to the temperature spectrum of the lamps that aquarists use.
https://www.researchgate.net/profil...ll-a-b-and-carotenoids-absorbance-spectra.png

 

[Deleted member 149562]

Sorry to take this completely off topic but are you actually growing plants with these lights?

I was looking at them the other day for a couple of ideas I had but didn't think they looked overly good.

I have had living plants under these lights...afterall they are infinitely adjustable on clour and intensity....but since my green thumb ability gave up and left home a few years ago, no live plants now unfortunately

 

[xxBarneyxx]

I have had living plants under these lights...afterall they are infinitely adjustable on clour and intensity....but since my green thumb ability gave up and left home a few years ago, no live plants now unfortunately

Thanks. My mother in law has a marine tank with a CFL fitting built into the lid. She wants to keep the lid as it is but the light is less than ideal. As its fish only one of these might be a good option for her and as its submersible I can fit it up without worrying about it getting wet or modifying the lid too much.

 

[FishHobby99]

Sorry to take this completely off topic but are you actually growing plants with these lights?

I was looking at them the other day for a couple of ideas I had but didn't think they looked overly good.

I am not using the fluval for plants. It’s for my big cichid/catfish tank.
no plants there. These guys make a mess playing in the sand. I use cheap whatever LEDs for the plants.

 

[Myraan]

Green light is present in the white light as well, as is the entire spectrum. While I agree that the color we see is what color is reflected by an object, that does not mean that none of that color is absorbed (or used) by an object. I've read quite a few articles by planted aquarists that have experimented with light spectrum and more than one has had more plant growth with green than without. What their controls were and how scientific their studies were I can not say, but I myself have seen significant plant growth with my current program.

Interesting.

The results people have found is likely because certain green excluding spectra harm the ability of carotenoids to absorb light and act as an accessory in photosynthesis. Plants in shady forests are probably evolved to use light with reduced red and blue to it's best use. I wonder if a lowering of red and blue compared to raw sunlight gives our aquatic plants an advantage over algae?

 

[noobfish]

Just want to clarify so I found this pic on bing. I think @noobfish knows this, this is just to help people realise the graph I found is a different thing to the temperature spectrum of the lamps that aquarists use.
https://www.researchgate.net/profil...ll-a-b-and-carotenoids-absorbance-spectra.png

That graph is from an article on how chloroplast protects chlorophyll from excess light absorption. It doesn't mean that green is not used at all though.

 

[noobfish]

Sorry for the slight highjack @JennySolano !

I am not using the fluval for plants. It’s for my big cichid/catfish tank.
no plants there. These guys make a mess playing in the sand. I use cheap whatever LEDs for the plants.

Well then none of this really matters for this application then, does it?!

Still a nice light though. At least it should last you a good long while (knock on wood)!

 

[FishHobby99]

Highjack away! Keeps the thread interesting!

 

[Byron]

If I my be permitted to correct a couple of things in past posts...

First, the situation in an aquarium with plants is different from those plants in their respective habitat. If you look at the videos of habitats in the Amazon basin for example, you will not see what most aquarists would consider "healthy" plants; they are usually spindling and algae-covered. Most of the plants are amphibious, spending half the year emersed and half submersed, and it is during the emersed period that they reproduce and grow most. The conditions we aim to provide in an aquarium have to be well thought out because we are providing far more ideal conditions in the water, but with that comes the problems like algae, oxygen/CO2 imbalance, light much too strong for fish, etc. None of this occurs in nature because the water courses that have plants (most do not) have fewer fish or the fish have refuge from all that light.

As for spectrum, as the graph posted in another post shows, aquatic plants require red and blue light to drive photosynthesis. Red is the more important, but blue is needed too. And while green light plays no part in photosynthesis, scientifically-controlled studies have proven that high green light improves the plants' response. Diana Walstad opinioned this was probably due to the additional intensity the green provides to the red and blue, and that natural sunlight is high in red, blue and green and the plants have evolved under this light, so naturally they will make the best use of it. Diana also notes that light having a colour temperature in the 5000K to 7000K range provides the best light for aquatic plants because it is high in the red, blue and green.

Many LED lighting units are too high in the blue; this is because they are largely aimed at marine tanks; blue light is prevalent in the ocean because it penetrates water much more effectively than red, so corals need strong blue light. Things are much different in freshwater. And too much blue does cause algae issues.

 

[FishHobby99]

great post, thanks Byron.

 

[FishHobby99]

I found a youtube vid of the Fluval Dynamic Effects. Don’t like it! It has bursts of bright lights like a strobe. Seems it would spook the fish. Sure would spook me if all a sudden the tank start flashing.