Brown Algae in Aquarium

Having brown algae in your aquarium can be a real nuisance. Not only does it look ugly, but it can also be harmful to your tank, especially any coral or vegetation that you have. Below we explore the details surrounding brown algae and take you through some solutions to help your get rid of the undesirable brown sludge in your tank!

What is Brown Algae?

Brown algae (Phaeophyceae) is a large group of multicellular algae. They are almost exclusively found in marine environments – generally in cooler coastal areas in the Northern hemisphere. There are not the “brown algae” that you are struggling with in your tank.

The brown algae in your aquarium is actually a diatom. These singular cellular organism are a microalgae and are often called Bacillariophyta. They contain the pigment xanthophyll which gives it the brown appearance.

What causes brown algae?

The diatoms are always present in your tank, but usually in numbers that are too small to see with the naked eye. They will, however, become very evident it the tank conditions are right for them to reproduce. There are two main trigger for brown algae appearance:

1. When you are setting up a new aquarium / cycling your tank. At this stage the brown algae will reproduce happily as it has minimal competition for nutrients.
2. Your tank has an excess of particular nutrients that the diatoms need to reproduce. These are covered in more detail in the removal guide below.

Remove brown algae in Aquarium

Wondering how to get risk brown algae? In order to remove the brown algae in your fish tank it is important to consider a number of factors that may be contributing to its growth. Below we outline how to remove the brown algae and how to stop it from coming back.

1. Wipe your tank

The easiest way to get started is to tank a cloth or sponge and carefully remove as much of the algae as you can. It will often have attached itself to the glass sides of your tank. Slowly wipe the side of the tank in an upwards direction to remove as much of the brown algae from the tank as you can (rinsing the cloth each time). Try to avoid disturbing the algae too much – you don’t want it floating through the water to other parts of your tank.

Wiping your fish tank won’t solve the problem with your tank being a breeding ground for the diatoms, but it will help you to immediately reduce the amount of algae present. Not only will this make your tank more visually appearing but it will also reduce the number of diatoms in your tank that are reproducing.

2. Reduce the amount of silicates in your tank

Brown algae feeds on silicates. It is very possible that the water you are adding to the aquarium has a moderate to high level of silicates already in it. In order to reduce the silicates (Silicon DiOxide in particular) from your tank it is worth considering a good quality Silicon DiOxide and Phosphate remover for your aquarium.

This will immediately have the effect of reducing the reproduction rate of the brown algae, and will help get your tank back to its pristine normality.

3. Use an aquarium vacuum

Using an aquarium vacuum has two main benefits:

1. It is a great way to remove brown algae from your substrate
2. It also helps to ensure removal of spare organic matter (such as uneaten food). This stops the organic matter from decomposing in your tank and giving off phosphates (brown algae also loves to feed on phosphates).

There are a number of good quality aquarium vacuums on the market today. You can find our favorites in our aquarium vacuum review article.

4. Reduce the amount of nitrates in your tank

Nitrates will always be present in your tank. It is important, however, that the levels are appropriate and not excessive. By keeping the level low will not only help to remove the brown algae but it will also help to ensure that your fish remain healthy. In order to find out the nitrate levels in your tank. There are some great test kits available that also test for pH and a number of other chemical levels at the same time.

5. Check your filter – or get a better one

Having the correct filter for your tank is incredibly important. You need something that is powerful enough to remove the waste levels of your tank and reduce clean water back into circulation. The size and type of filter you need will depend on the size of your aquarium and the inhabitants of your tank.

Having a sufficiently powerful filter will also help to ensure that you have some water flow in your tank. Brown algae loves stagnant water – so don’t give it any! One option is to look for a decent Aqueon filter.

Taking it cone step further, it is worth consider an aquarium UV sterilizer. These help kill free floating algae – ensuring that your tank remains crystal clear and clean. As a second benefit they also help stop the spread of microorganisms from one animal to another – thus helping minimize / prevent disease if you tank.

Brown Algae in Aquarium – Conclusion

Diatoms / brown algae can be a real nuisance. Not only does it look bad, but it can be harmful to your plants (and coral if you have any). If you tank becomes overrun with brown algae don’t panic. Following the guide above should help return your aquarium to its former glory.

Good luck!