How to get rid of black beard algae?
Nuisance Algae: How to get rid of black beard algae

Most people in the aquarium hobby have heard of the dreaded black beard algae. It grows like crazy and covers every inch of your aquarium, both decorations and plants, at an alarming rate. Killing the plants and forcing you to scrub your decorations to remove this troublesome algae. This article will detail why this algae occurs and how to address the underlying causes of this algae. A few aquarium fish species will consume this algae. By the end, you should be able to easily modify your aquarium to either get rid of or prevent the growth of the dreaded black beard algae.



Three underlying causes aid in the development and growth of black beard algae. They are excess light, inadequate CO2, and excess nutrients as a result of organic waste. Though these will all cause and exacerbate the spread and growth of black beard algae, there are simple steps to reduce the risk of this occurring.

Let's start with the easiest change to reduce the spread, of excess organic waste. Also known as fish poop which causes excess nitrates and phosphates. While nitrates and phosphates are essential macronutrients for plant growth, excesses of these can contribute to algae issues and are often released as a result of the breakdown of fish waste. By bettering your maintenance and reducing the amount of organics in the aquarium you can fix this underlying factor. Increase your water changes and siphon off the substrate and this will help reduce the growth and spread of black beard algae within your aquarium.

The final two causes are quite intertwined and can be addressed with a simple change to your aquarium. Excess light is a cause of low CO2 levels within the aquarium - let's quickly explain why this is. When plants photosynthesize they use up the CO2 in the water column. CO2 is diffused into the aquarium at a constant rate through surface agitation (surface movement) and will supply plants with available carbon to use in growth. The higher the light level, the more Co2 plants will use during photosynthesis. To address the issue of low CO2, you can do one of two things. Either lower the amount of time the light is on or reduce the intensity of the light in question. By lowering the light level and time it's on, you will reduce the amount of CO2 being used by the plants. As a result, the CO2 levels will not be excessively low and trigger the growth of black beard algae.



The above describes how to prevent and reduce the spread but not how to get rid of an established infestation of black beard algae. You have a couple of options for removing and combating an infestation of this algae variety.

First is using a liquid to kill the algae. The two commonly used products are hydrogen peroxide and seachem excel. The recommended way to dose it is to suck it into a syringe and directly spray it onto the black beard algae. This should severely damage the algae, causing it to turn pink and then white before finally dying. Once it turns a light pink it should be easier to scrape or scrub off and should then be manually removed. The only way to get rid of a black beard algae infestation is first to manually remove it, and then address the underlying causes to prevent it from returning.


There is one other option to remove black beard algae in the aquarium if you prefer not to use chemicals to kill it. First, you must address the underlying cause and then add a herbivorous species to consume the black beard algae. There are not many species that vigorously eat black beard algae but there are three which eat it readily. The first is the Siamese algae eater, which is an herbivorous algae eater that is commonly mixed up with the flying fox and Chinese algae eater. While those other two species eat black beard algae as juveniles, they will stop eating it as they mature and have a change in diet. Meanwhile, the Siamese algae eater is known to consume black beard algae throughout their whole life. However, they'll consume more as juveniles since they are actively growing during their development. The second species that will consume blackbeard algae is the Florida flag fish. This is a North American killifish species that is omnivorous but is known to actively eat black beard algae in the aquarium. This is an attractive and unique species in the aquarium hobby. While they will eat pellets and flakes they will also consume black beard algae readily. The last species is not a vertebrate but a shrimp. We’re talking about the amano shrimp. This species is a great algae eater and actively eats and preys on hair algae including black beard algae.



Now you know the cause of black beard algae and various ways to combat its spread and development. So remember, algae is simply a fringe organism resulting from various deficiencies that occur within the aquarium. By understanding this and the causes of the specific algae you'll be able to easily address the issue and get rid of the algae.


Written by Jacob Thompson

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