Mixed lighting for fast plant growth

[neidzwiedz]

Hello all,

I’ve got a relatively new tank set up and I’m trying to get the plants grown out as fast as possible and still keep them healthy and robust. 
the lighting I am currently using is full spectrum an lights the tank well.  I remembered this evening that I had an RGB LED strip light i fabricated a while ago, so I decided to get it out and see if it will help at all.

my question is, should I set it to red or blue or cycle the two, ie red for four hours then blue for four hours, or some other combination. 
 

Thanks

Edited January 13, 2023 by neidzwiedz

[lefty o]

im no expert, but dont run tons of blue. blue light really seems to grow algae well.

[Rube_Goldfish]

If I'm remembering what @Seattle_Aquarist had to say on the matter, light color doesn't matter except that, all else being equal, blue light with its shorter wavelength will penetrate deeper water, but otherwise all light in the visible spectrum will contribute equally to photosynthesis. (Roy, do I have that right?)

[Seattle_Aquarist]

On 1/13/2023 at 7:04 AM, Rube_Goldfish said:

If I'm remembering what @Seattle_Aquarist had to say on the matter, light color doesn't matter except that, all else being equal, blue light with its shorter wavelength will penetrate deeper water, but otherwise all light in the visible spectrum will contribute equally to photosynthesis. (Roy, do I have that right?)

Hi @neidzwiedz

All of those colors will contribute to increased growth so chose a color that enhances your enjoyment of the tank.  @Rube_Goldfish is correct that the blue spectrum does penetrate to deeper depths than other colors.  As for 'blue light' causing algae it is a myth ..... research has shown that algae has basically the same "action spectrum" as regular plants meaning that the same colors that grow plants also grow algae.    Algae growth is a result of light (intensity/duration), nutrients, and water flow.  -Roy

[neidzwiedz]

Thanks guys, that’s kinda what I thought but I figured I’d ask the experience. 

[Darax]

Are you using CO2? If not light may not be the limiting factor. 

[Ninjoma]

On 1/13/2023 at 7:35 AM, Seattle_Aquarist said:

Hi @neidzwiedz

All of those colors will contribute to increased growth so chose a color that enhances your enjoyment of the tank.  @Rube_Goldfish is correct that the blue spectrum does penetrate to deeper depths than other colors.  As for 'blue light' causing algae it is a myth ..... research has shown that algae has basically the same "action spectrum" as regular plants meaning that the same colors that grow plants also grow algae.    Algae growth is a result of light (intensity/duration), nutrients, and water flow.  -Roy

Does that mean there is no merit to these experiments conducted by MSU, concluding that red light grows plants faster than green or blue? https://www.canr.msu.edu/news/green_light_is_it_important_for_plant_growth#:~:text=Green light is considered the,for photosynthesis%2C they reflect it.

I also might be completely misunderstanding what you're saying. 

[Seattle_Aquarist]

On 1/13/2023 at 5:21 PM, Ninjoma said:

Does that mean there is no merit to these experiments conducted by MSU, concluding that red light grows plants faster than green or blue? https://www.canr.msu.edu/news/green_light_is_it_important_for_plant_growth#:~:text=Green light is considered the,for photosynthesis%2C they reflect it.

I also might be completely misunderstanding what you're saying. 

Hi @Ninjoma

Possibly I did not express myself clearly.  Plant utilize all spectrum of light.  Some light spectrum (mostly in the violet/blue) produce more photosynthesis and growth, other light spectrum (orange/red) promote flowering and leaf size even the green spectrum promotes certain chemical processes in plants and leaves.  That is why 'red light' is typically used in hydroponic farming facilities.

That's an interesting article, the problem is most sensors used to measure PAR back in 2014 were very poor at accurately measuring PAR in the blue spectrum tending to dramatically under record the actual PAR.  There have been substantial improvements since the experiment was conducted.

As I stated to the OP if light is a limiting factor for growth then adding additional light will help and chose a color that enhances the enjoyment of the tank.  I guess if I wanted crazy plant growth in a tank I would use just 'red' light but I would hate to look at my plants and fish that way.  lol
 -Roy