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Fluffy pale algae (opinions/advice please)

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Fish Crazy
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Aug 6, 2023
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I've noticed this fluffy, hair-like algae on parts of my mangle wood. Could this be the beginning of a black beard algae break out? Hopefully nothing detrimental to my fish or impossible to resolve.

  • Retrofit Day & Night (LED)
  • Aquarium light on for 7 hours each day
  • 6500k (kelvin rating)
  • 14W
NutrientsSeachem Flourish Comprehensive, at a lower dose than on the label.
Water Changes Weekly 30-50% water changes
(The last water change was November 11th)
No ammonia or nitrite readings, with nitrate of about 7ppm which is the level of nitrates in my tap water.


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I'm sorry to single you out Byron, but you were really helpful with my brown algae problem before and I could use a second opinion and pair of eyes 😁
In your opinion is this something I need to act on or is it just ugly and harmless?
Hello. This fluffy looking form of algae isn't as much of a problem as others. It will grow on very smooth surfaces. I've had it grow on the plastic tubes that extend from my sponge filters. It has a natural look I actually like because in time it covers the smooth surfaces of mechanical equipment in the tank. Algae is difficult to control because it can grow in water with a nitrate level of 10 ppm (parts per million), that's not much. You can increase the amount of water you change and change that amount more often. This will at least limit the algae growth. Or, you can remove the affected piece and scrub it with a heavy bristled brush.

As I told you previously (I think), "problem" algae needs to be controlled, and that is easy with a balance of light and nutrients. The photos suggest another form of black brush algae, but it really does not matter. Get the balance between available light and nutrients sorted out, and that is the end of problem algae.

What shows in the two photos is not in my view much of a problem. Let alone on wood, I do just that, leave it alone. It is only when it begins to appear and spread on plant leaves that you have a "problem" algae.

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