How to get rid of black algae

[Navfish]

I have algae in the tank and it looks god awful and I need to get it out asap. Is there anything I could you to get it out?

I looked it up online and it said to reduce the brightness but my light only has one setting. I tried to put the light on for fewer hours but still hasn’t worked.

I also did frequent water changes, getting the nutrients in the water which it said would work online.

But nothing works!!

I don’t want to get rid of the plants.

 

[glyn]

In order for us to help, can you tell us about your tank, its inhabitants and its filtration....

 

[Bluebubbles]

Ensure your water parameters are good and your tank maintenance is consistent. If you’re using plant fertilisers make sure you’re not overdosing the tank. Continue to reduce the time your lights are on for. Another cause is unstable or low CO2 levels. You can get liquid carbon additives but i haven’t got any experience with those.

 

[Byron]

As a background--common green algae is natural and normal in a healthy aquarium, and not a problem. But what I term "problem algae" like the black brush algae pictured here is indeed a problem especially in a planted tank. It has a cause and there is only one way to deal with it.

The cause is an imbalance in the light and nutrients. Plants need sufficient light to drive photosynthesis (this varies by species) and adequate nutrients in balance. As soon as any one factor in this balance is missing, algae has the advantage. So, you establish or re-establish the balance. This involves the light (intensity, spectrum and duration) especially, along with the nutrients which come from feeding fish, water changes, and fertilizers.

If you can provide some data on the light and any fertilizers, we should be able to help you sort out the issue.

 

[Navfish]

As a background--common green algae is natural and normal in a healthy aquarium, and not a problem. But what I term "problem algae" like the black brush algae pictured here is indeed a problem especially in a planted tank. It has a cause and there is only one way to deal with it.

The cause is an imbalance in the light and nutrients. Plants need sufficient light to drive photosynthesis (this varies by species) and adequate nutrients in balance. As soon as any one factor in this balance is missing, algae has the advantage. So, you establish or re-establish the balance. This involves the light (intensity, spectrum and duration) especially, along with the nutrients which come from feeding fish, water changes, and fertilizers.

If you can provide some data on the light and any fertilizers, we should be able to help you sort out the issue.

In order for us to help, can you tell us about your tank, its inhabitants and its filtration....

So the tank above is a 37 gallon tank with

1x angelfish
4x peppermint tetras
2x mollies

I have had the tank since September 2022 and has been running since then. I have 2 air pumps at the top of the tank for more oxygen and a filter at the top which is adequate for the tank.

I have a bright light that runs in the tank and is by. No means dim but since there is no dim setting, I can’t turn it down

The water quality is also fine as in 0 ammonia and nitrite

I do use seachem flourish for the plants but haven’t used it in about 2 weeks as I had a disease spread throughout the tank.

I noticed the issue about a 1 and a half months ago.

 

[Byron]

Since the light is a given, we can consider duration--how long each 24-hour period is the tank light on? And do you know the spectrum, which could be the Kelvin rating or the CRI, either may be on the unit or the manufacturer's website.

Just to clarify on the fertilizer, if this is the Flourish Comprehensive Supplement for the Planted Aquarium, fine, though less may be worth consideration but let's deal with the light first. But be careful not to overdose the Flourish, I have had brush algae increase from not using enough and from using too much.