Does Actinic/Blue Light Cause Algae Growth?

[Adamantium]

Hi there! I have a relatively new tank (~3 months) that is still going through the uglies.

I've got a bit of slime-like algae covering parts of my sand bed, and I want to try a blackout to eliminate it. My parameters seem to be in check (0 ammonia, 0 nitrite, ~0 nitrates and ~0 phosphates), so I'm thinking this might do the trick.

My question is: Does leaving my actinic light cycle going during this "black out" reduce it's effectiveness, or would it still be pretty effective?

I have to imagine it would still grow some algae, but would it be a significant reduction just turning off my daylights?

Thanks for any insight!

 

[hearttx]

I would turn them completely off for 3 days . The actinic light would still feed the algae.

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[Adamantium]

I would turn them completely off for 3 days . The actinic light would still feed the algae.

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Drat. I figured it would, but was hoping it would be a significant enough drop off that I could leave the actinics on.

I just want to be able to view the tank. Going three days without is going to be hard

Thanks for the reply!

 

[DiscusHeckel]

"Slime algae" is actually not algae. It is cyanobacteria. When you turn off your lights, they will disappear and then will come back once the lights are back on again.

They are a symptom of imbalance between available nutrients and their consumers in a reef tank in that there is probably not enough algae in your tank to compete with cyanobacteria. Cyanobacteria usually thrive under low (or zero) NO3 conditions where nutrients are plentiful, whereas algae cannot. This is because cyanobacteria can get the required nitrogen directly from atmosphere. For this reason, they are also known as nitrogen fixing bacteria.

 

[Adamantium]

"Slime algae" is actually not algae. It is cyanobacteria. When you turn off your lights, they will disappear and then will come back once the lights are back on again.

They are a symptom of imbalance between available nutrients and their consumers in a reef tank in that there is probably not enough algae in your tank to compete with cyanobacteria. Cyanobacteria usually thrive under low (or zero) NO3 conditions where nutrients are plentiful, whereas algae cannot. This is because cyanobacteria can get the required nitrogen directly from atmosphere. For this reason, they are also known as nitrogen fixing bacteria.

Very interesting. Thanks for the insight. I have to imagine you're right since my nutrient levels are so low.

I don't think I overfeed, though. I'm pretty conservative. Any suggestions on how to deal with this in the long term?

 

[Adamantium]

Actually, sorry, I'm not sure I understand what you mean when you say NO3 levels are low, but nutrients are high. Isn't NO3 a nutrient?

 

[hearttx]

It is but your reading will be low because the bacteria is using it as a food source and consuming it.

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[Diana A]

I will assume there are no corals in the tank. There is no need for the lights to be on. Even fish don't need the lights

 

[Adamantium]

I will assume there are no corals in the tank. There is no need for the lights to be on. Even fish don't need the lights

There are, actually. Softies. They seem to be doing well, and from what I understand, a 3 day blackout shouldn't harm them, right?

 

[Percula9]

Water changes to lower nutrient levels

 

[Uncle99]

The tank is still young
The blackout will hurt nothing
If you keep your water perfect, all this and more will go away in time.