Blue lights for algae?

[Salt Addiction]

So I wanted to confirm this. I remember reading somewhere running only the blue spectrum of your lights for a time will kill hair algae as it uses the white/red spectrum for energy? Trying to dail back the ammount in one of the tanks without starving the anemones.

 

[TheShrimpNibbler]

This isn’t exactly right, but it is along the correct lines. Algae still uses blue light, but they also use other spectrums such as red light. That’s why a lot of plant lights look purple. Corals on the other hand tend to use a much higher ratio of blue light to other spectrums, but they also don’t use only blue light. So only blue light isn’t ideal for algae or corals. The best option would be to dial back white, green, and red spectrums to a lower level, but keep blue high.

 

[Salt Addiction]

Thanks! I have it 100% Blue right now with White zeroed out. Thinking though maybe instead of doing a week or two blue that a 3 day blackout may be more effective, I just worry my nems will decide to travel in search of light if I do.

 

[TheShrimpNibbler]

I personally wouldn’t do the blackout. I think that they ignore what’s causing the algae and only temporary fix it. I would recommend testing your parameters and determining what permanent change needs to be made to keep algae gone.

 

[Poof No Eyebrows]

Depending on the lights your using the nems probably won't notice that much for such a short period, at least mine havent when I've run blue at 100 and dropped white to 10 (red sea 90's)

 

[Salt Addiction]

Water params are good and it's on the retreat, the initial bloom was caused when I shut my skimmer down for a week because I forgot to turn it back on after maitenance.

I have guests coming over end of the week so I was trying to have it cleaned up by then lol. On a side note though I will say my Foxface is very happy with this development...and currently very fat lol.

Edit: Also I had a trigger in there before that eliminated my CUC, hes gone now.

 

[FBAA]

My lawnmower blenny keeps it quite clear of hair algae and he has a lot of character. Also as far as lighting the red/near IR + blue spectrum makes algae grow faster due to the "Emmerson effect". It's worth looking into. Going dark or all blue isn't going to solve the problem quickly. Check your nitrates and phosphates.

 

[blasterman]

Light spectrum has nothing to do with algae growth. Light spectrum has nothing to do with inhibiting algae growth.

Anybody telling you to turn off white LEDs needs to be ignored. A white LED is mostly blue spectrum.

Corals use algae to convert light to energy. See how silly this is.

 

[monkeyCmonkeyDo]

White leds are blue spectrum? What? Lol...
D

 

[TheShrimpNibbler]

Light spectrum has nothing to do with algae growth. Light spectrum has nothing to do with inhibiting algae growth.

Anybody telling you to turn off white LEDs needs to be ignored. A white LED is mostly blue spectrum.

Corals use algae to convert light to energy. See how silly this is.

I don’t mean to sound rude, but this is simply not correct. Light spectrum has everything to do with the growth of anything photosynthetic. Although a white led does have some blue in it, it also contains green, red, yellow, and other spectrums of light in it. These are what can cause the extra algal growth, not the blue light within the white. Chlorophyll does not absorb all light for photosynthesis the same. For example, Chlorophyll a, which is responsible for a portion of the photosynthesis in algae, absorbs light in the blue to violet range, and the red to orange range. This is exactly why people suggest turning down red light for algae. It is also why most plant lights appear purple from a combination of red and blue light. Please do not tell people that spectrum does not matter, it very much does. Also the xooanthella that is symbiotic algae inside of corals is not the same as the algae that grows in the rest of the tank. They do have some of the same types of chlorophyll and photosynthetic pigments, hence why they both need blue light, but they also vary in some ways. I hope this helps you understand why spectrum does matter, and I am sorry OP for this long post sidetracking the thread.