Reduce algae by turning off white light?

[mike550]

Hello! I have a tank that’s already bio-diverse and many of the creatures (et anemones and some corals) need light. But I’m also going through a bit of an algae outbreak. I’m wondering if I turn off the white LEDs and only have the tank run the blue region if that will help reduce the algae and still support the folks that need light?

If you want numbers
Salinity 1.025
Alk 8.8
Nitrates 6
Phosphate 0.05
Calcium 390
Magnesium 1400

Thanks in advance

 

[laezur]

It will slow it down, yes, but algae can still use some blue light I believe. Many people run lower/0 whites for aesthetics and to keep algae manageable.

 

[Stephen Glover]

You can keep your white, green and red down and your blues up and see if it helps.

 

[srobertb]

How old is your tank?

What do you mean by “bio-diverse?”

Photosynthetic creatures can adapt to a wide range of lighting. The key word here being adapt. Changing the spectrum will be disruptive to the creatures under the light if done frequently. Changing the tank to very blue for a few days probably not going to be a big deal. With that in mind, dimming the existing light temporarily vs changing the spectrum may be a better solution while you work to remedy the underlying issues. Some people may black out their tank for a brief period too.

I don’t know your lights or spectrum settings. It’s generally held that algae enjoys the red spectrum (to oversimplify) which makes light look whiter but plenty of algae free tanks run at 10,000K And 6500k and have done so long before I was around.

Why do you have algae issues? Is it a normal part of your tanks maturing process? Are you within the first year or so? Do you overfeed? Have you introduced a lot of that “bio-diversity” in a short time period? Do you have proper flow? Do you have a proper clean up crew? Do you have something to outcompete the algae for nutrients (water changes, refugium, algae scrubber, bio-pellets, etc)

Algae grows when there is sufficient light, nutrients, and a place for it to take hold pending a lack of predators.

 

[ReefEco]

I wouldn't expect shifting your lights to blue or would impact much of your algae growth significantly, but it might effect the corals adversely more so whose biology has become adapted to the particular spectrum you are providing. Srobertb asks a lot of good questions, since algae cropping up is dependent on a range of factors. However, typically an algae problem is actually an herbivore problem - i.e. not enough of them to keep it at bay. Clean up crew and fish are your best bet, as well as manual removal to get ahead of it and ensure critters will eat it. Some clean up crew and fish won't touch it once it gets too long, preferring to eat close cropped algae on rocks.

 

[mike550]

How old is your tank?

What do you mean by “bio-diverse?”

Photosynthetic creatures can adapt to a wide range of lighting. The key word here being adapt. Changing the spectrum will be disruptive to the creatures under the light if done frequently. Changing the tank to very blue for a few days probably not going to be a big deal. With that in mind, dimming the existing light temporarily vs changing the spectrum may be a better solution while you work to remedy the underlying issues. Some people may black out their tank for a brief period too.

I don’t know your lights or spectrum settings. It’s generally held that algae enjoys the red spectrum (to oversimplify) which makes light look whiter but plenty of algae free tanks run at 10,000K And 6500k and have done so long before I was around.

Why do you have algae issues? Is it a normal part of your tanks maturing process? Are you within the first year or so? Do you overfeed? Have you introduced a lot of that “bio-diversity” in a short time period? Do you have proper flow? Do you have a proper clean up crew? Do you have something to outcompete the algae for nutrients (water changes, refugium, algae scrubber, bio-pellets, etc)

Algae grows when there is sufficient light, nutrients, and a place for it to take hold pending a lack of predators.

@srobertb thanks for your thoughts. Just a quick summary

Tank is around three years old and to your point eveything was fine until I switched to pellet food because I went on vacation. I suspect that the HikarI Seaweed Extreme may have triggered the algae. Thats really the only tangible change. So it’s also my suspect.

Regarding lights I think I’ll leave as is. I’d rather not make sudden moves that create other issues

 

[srobertb]

@srobertb thanks for your thoughts. Just a quick summary

Tank is around three years old and to your point eveything was fine until I switched to pellet food because I went on vacation. I suspect that the HikarI Seaweed Extreme may have triggered the algae. Thats really the only tangible change. So it’s also my suspect.

Regarding lights I think I’ll leave as is. I’d rather not make sudden moves that create other issues

One of the best lessons I learned was to set my flow and lighting and leave it alone. Stable and imperfect > than constantly tweaking.

Food will do it. Maybe it’s the amount I feed of pellets but TropicMarin food dirties the glass quicker than As a habitual over feeder I can tell when it’s time to cut back a bit (although my issue is glass-related and thankfully never on the rocks).

Long story short my tank leaked and everything is in a temp holding tank now. I scaled back to once a day feeding to try and limit instability issues and saw absolutely no change in fish size or temperament. They’re still very fat. I think they just moved on to actually working for food as they pick at the rocks more frequently. I also installed a hang-in-tank refugium and put some Chaeto in there to help with instability. My foxface and tang love picking at whatever strands pop out. You could consider running something like that temporarily until your algae problem goes away.

In any case, less food for a couple days or a week is a great idea I didn’t think of.

 

[mike550]

Thanks @srobertb to your point I’m going back to no sudden moves and minor adjustments. So “seaweed extreme” is out. Now a mix of Hikari and Piscine. I’ll back off on that and go back to frozen.

I’ll also had some more astreas and turbos. Maybe a tuxedo urchin. Much appreciated