Reef lighting spectrum question

[trsmith18]

Ive been dealing with a green algae outbreak and have made significant headway. In order to minimize its return Im evaluating sources from growth.

Regarding light spectrum which one(s) (red, blue, green, white) fuels nuisance algae growth? What are you guys currently using spectrum wise to optimize coral growth but minimize algae.

Obviously this isn't the only adjustment im making for this problem, but want to evaluate my lighting schedule and spectrum.

 

[ISpeakForTheSeas]

Ive been dealing with a green algae outbreak and have made significant headway. In order to minimize its return Im evaluating sources from growth.

Regarding light spectrum which one(s) (red, blue, green, white) fuels nuisance algae growth? What are you guys currently using spectrum wise to optimize coral growth but minimize algae.

Obviously this isn't the only adjustment im making for this problem, but want to evaluate my lighting schedule and spectrum.

Typically blues and reds are used the most for photosynthesis (for both algae and corals) though, there is some slight green and yellow usage too. That said, I doubt changing up the lighting will do much to help with the algae issues (for the long explanation of why, see the quotes below, including the linked thread in one of the quotes).

Some people believe that by only using blue lighting, they will limit algae growth/give coral an edge to outcompete algae. I find these claims to be pretty dubious personally, as most algae species utilize blue light as well, but it's possible there may be some small anti-algal/pro-coral effects.

I have a couple of posts on the thread linked below* discussing using blue lighting for algae control that go into a bit more detail, but - to be brief - using lighting to control algae doesn't seem to be anywhere near as effective as many people make it out to be. It may help limit a few types of algae, but I personally wouldn't run all blue lighting to try and prevent algae - if I was going to run all blue lighting, it would be to get a good fluorescent pop from my corals.

* The thread: https://www.reef2reef.com/threads/w...olor-here-to-stop-algae.919937/#post-10338958

I haven't looked much into the tail ends of the spectrum, but a few people swear by infrared lighting as being beneficial to corals, and I know that UVA lighting does have a positive impact on the fecundity of at least a few animals (such as Ghost/Grass Shrimp). So, while the tail ends of the spectrum may not be needed, there may still be some benefit in providing them for your tank regardless.

(Image from here: https://www.rseco.org/content/122-chlorophyll-absorption-and-photosynthetic-action-spectra.html )

(Image from here: https://www.researchgate.net/figure...he-2-carotenoids-peridinin-per_fig1_262967859 )

Long story short, as long as the wavelength is right and the output (PAR) is right, the red and blue lighting should be able to grow pretty much anything just fine (though a little bit of green/yellow/orange lighting likely wouldn’t hurt your prospects for slightly better growth).

 

[trsmith18]

Thanks for the reply. Again suggestions of color intensity/percentage...recognizing it make make a minimal effect?

 

[Spare time]

In a reef tank, algae should not be limited by light, but rather predation and competition. If you change the lights or water chemistry to not be suitable for algae, you also make it unsuitable for corals

 

[ISpeakForTheSeas]

Thanks for the reply. Again suggestions of color intensity/percentage...recognizing it make make a minimal effect?

Basically, a lot of people say that any light that isn’t blue will grow algae.

As shown in my post above, though, most algae will use the same light spectrums as corals (including blue). So, any algae reduction benefits of running pure blue light will likely be very small (and the benefits might just be that the algae is harder to see compared to the fluorescent corals in pure blue light).

In short, if you run all blues, you will still get algae, and your tank will look like a giant windex container - this would make the coral colors pop really well because of their fluorescence, but it may make viewing the fish less enjoyable.

 

[Spare time]

Basically, a lot of people say that any light that isn’t blue will grow algae.

As shown in my post above, though, most algae will use the same light spectrums as corals (including blue). So, any algae reduction benefits of running pure blue light will likely be very small (and the benefits might just be that the algae is harder to see compared to the fluorescent corals in pure blue light).

In short, if you run all blues, you will still get algae, and your tank will look like a giant windex container - this would make the coral colors pop really well because of their fluorescence, but it may make viewing the fish less enjoyable.

I think people forget that zooxanthellae in coral IS algae