Is this... algae?

[sporkman]

I first saw some black... something on a silk plant and didn't think much of it, maybe just some fluke or something.

After some time, I noticed that I was seeing this on other plants (they are all either plastic or silk). I've seen reference to something called "beard algae", but this stuff looks even darker. Any ideas what I'm looking at and whether it's harmful?

 

[Colin_T]

blue green algae (aka Cyanobacter bacteria).

It loves nutrients and low oxygen levels but can grow anywhere there is water.

If you are feeding flake food, reduce the amount you use and add frozen (but defrosted) or live foods instead.

Do big (75%) daily water changes and gravel clean the substrate. try to suck the algae off the plants and ornaments or tank them out and hose them off before putting them back in the tank.

If you have fluorescent globes above the tank, check the age and Kelvin (K) rating on them. Globes that are more than 12 months old can encourage this, and globes with a low Kelvin rating (below 5000K) can also encourage it. As fluorescent globes get older, their Kelvin rating drops.

If you use LEDs, they are fine and don't change over time. However, you should check the light in them because too much red or yellow light, and not enough blue light can cause it.

 

[sporkman]

Thanks, and sorry for taking so long to ask...

So even though it's jet black, it's called Blue-Green Algae, and even though it's called an algae, it's bacteria!? OMG, I should have went back to guinea pigs.

Just to be 100% clear, this is not a trick of photography - this stuff is black. When I google "Cyanobacter" I get images that look more... blue/green? Could it be "black beard" algae?

No fish yet, so my options are many... Tank is cycled so I don't want to destroy that work though...

 

[Byron]

Thanks, and sorry for taking so long to ask...

So even though it's jet black, it's called Blue-Green Algae, and even though it's called an algae, it's bacteria!? OMG, I should have went back to guinea pigs.

Just to be 100% clear, this is not a trick of photography - this stuff is black. When I google "Cyanobacter" I get images that look more... blue/green? Could it be "black beard" algae?

No fish yet, so my options are many... Tank is cycled so I don't want to destroy that work though...

If it comes off from surfaces like a slime using your fingertips, it is cyanobacteria. This is a photosynthetic bacteria, not an algae, though many mistakenly assume the latter. While not specifically harmless in itself, it does indicate an organics problem that can be harmful to fish and plants. It can be various shades of green and there is a red cyanobacteria more common in marine environments than freshwater. It is caused by organics in the presence of light.

 

[sporkman]

Hmmm... So no fish, no food, no live plants, and I already have problems. Ugh.

Also it is LED lighting - there's a row of "warm white" LEDs and one of blue. I had exclusively been using the white LEDs...

I guess for now I just physically clean the plastic plants and see if it comes back? And if it doesn't, start my fish shopping?

 

[angelcraze]

Cyano can be blue, green, black and even red. So you didn't even add anything live from the store yet? Goes to show it doesn't have to be introduced....

I have battled cyano on occasion in different tanks. It likes to persist in my 120g right now, but I used to have it in my 90g and I haven't seen it in 4 years there, so it is possible to keep it from coming back.

Did you already cycle your tank? I would at least rinse those plants well under tap water. A dip of 3:1 water/hydrogen peroxide for at least 6 minutes would make sure to kill any spores.

I remove it any chance I get.

And actually fast growing live plants would help to outcompete cyano by using up the nutrients. It's easy to add a floating plant. Some do better in hard water than others, so it depends on your water hardness which ones would be your best bet.

 

[ChefAlex]

Hmmm... So no fish, no food, no live plants, and I already have problems. Ugh.

Also it is LED lighting - there's a row of "warm white" LEDs and one of blue. I had exclusively been using the white LEDs...

I guess for now I just physically clean the plastic plants and see if it comes back? And if it doesn't, start my fish shopping?

If you have no live plants yet as you say, simply shut the lights off. That will solve most of the problem.

Wipe the plastic plants clean, shut off the lights and do a 100% water change before adding any fish. That should be all you’ll need to do.

A little bit of algae in going to happen in nearly every tank. Keeping nutrients in check, not having excess lighting and utilizing hardy live plants that will compete will algae should keep you far ahead of algae.

 

[sporkman]

I am the slowest tank builder ever.

I am algae (or whatever) free it seems. I did a large water change and also went months without lights so...