Why Have I Got Brown Algae in My Aquarium?

Brown algae can be an aquarium owner’s worst nightmare; not only does it not look appealing, but brown algae can also cause a whole host of problems for the wellbeing of your fish population. Brown algae can be toxic, harmful and damaging to both the fish and plants that inhabit your fish tank, so it’s important you do everything you can to keep it under control. Luckily there are certain ways you can avoid, reduce and get rid of brown algae.

What is brown algae in my fish tank?

If your once new, shiny aquarium tank has started to become overpowered by brown coloured patches, then you’ve fallen victim to brown algae. Brown algae is actually formed from billions and billions of microscopic creatures called diatoms. These creatures intertwine and form the clumpy brown patches that invade your fish tank; sticking itself to the glass, plants and equipment installed in your aquarium. 

What causes brown algae in aquariums?

Now you know what it is, it’s important to understand what causes brown algae to appear. 

High Nitrate Levels

Just as we discuss in our blog How To Reduce Phosphates and Nitrates in an Aquarium, nitrate levels can rise because of the waste that inhabits your fish tank. From food waste, fish excrement and dying plant life, all of these create the harmful chemical ammonia. The media in your filter then converts this ammonia into nitrates.

Following our tips in reducing your nitrate levels, such as: not overfeeding your fish, regular tank maintenance, not overstocking your tank and thinking carefully about the stock and media you put in your tank, you’ll be able to avoid nitrate levels causing unnecessary problems and creating brown algae.

High Phosphate Levels

Similarly, phosphates are the chemicals produced when waste is breaking down in your tank’s water. This encourages algae to bloom and can create a harmful environment for your fish to live in. Following our advice on regular maintenance and correct filtration, you should be able to avoid harmful phosphate levels and keep brown algae risks under control.

Poor Aquarium Lighting

The most infuriating thing about brown algae is that it thrives in the conditions where green algae cannot, meaning you’re most likely always going to be battling one or the other. If your tank has lower lighting, there’s a good chance it is too dark for green algae to photosynthesise. However, this might encourage brown algae growth! 

Green algae can be much easier to remove than brown algae, so if possible, it might be worth considering lighting your aquarium better. Take a look at our guide to Aquarium Lighting and ensure you’re following the best advice.

Bad filtration

Having poor filters in your tank can be another cause of higher nitrate levels. This then encourages the growth of brown algae within your tank and creates a problem for you. Ensuring you have the correct mechanical filtration to remove debris, uneaten food particles and fish waste will help keep the brown algae at bay.

How To Remove Brown Algae From Your Fish Tank

Brown algae can be an aquarium owner’s worst nightmare; not only does it not look appealing, but brown algae can also cause a whole host of problems for the wellbeing of your fish population. Brown algae can be toxic, harmful and damaging to both the fish and plants that inhabit your fish tank, so it’s important you do everything you can to keep it under control. Luckily there are certain ways you can avoid, reduce and get rid of brown algae.

What is the brown algae in my fish tank?

If your once new, shiny aquarium tank has started to become overpowered by brown coloured patches, then you’ve fallen victim to brown algae. Brown algae is actually formed from billions and billions of microscopic creatures called diatoms. These creatures intertwine and form the clumpy brown patches that invade your fish tank; sticking itself to the glass, plants and equipment installed in your aquarium. 

What causes brown algae in aquariums?

Now you know what it is, it’s important to understand what causes brown algae to appear. 

High Nitrate Levels

Just as we discuss in our blog How To Reduce Phosphates and Nitrates in an Aquarium, nitrate levels can rise because of the waste that inhabits your fish tank. From food waste, fish excrement and dying plant life, all of these create the harmful chemical ammonia. The media in your filter then converts this ammonia into nitrates.

Following our tips in reducing your nitrate levels, such as: not overfeeding your fish, regular tank maintenance, not overstocking your tank and thinking carefully about the stock and media you put in your tank, you’ll be able to avoid nitrate levels causing unnecessary problems and creating brown algae.

High Phosphate Levels

Similarly, phosphates are the chemicals produced when waste is breaking down in your tank’s water. This encourages algae to bloom and can create a harmful environment for your fish to live in. Following our advice on regular maintenance and correct filtration, you should be able to avoid harmful phosphate levels and keep brown algae risks under control.

Poor Aquarium Lighting

The most infuriating thing about brown algae is that it thrives in the conditions where green algae cannot, meaning you’re most likely always going to be battling one or the other. If your tank has lower lighting, there’s a good chance it is too dark for green algae to photosynthesise. However, this might encourage brown algae growth! 

Green algae can be much easier to remove than brown algae, so if possible, it might be worth considering lighting your aquarium better. Take a look at our guide to Aquarium Lighting and ensure you’re following the best advice.

Bad filtration

Having poor filters in your tank can be another cause of higher nitrate levels. This then encourages the growth of brown algae within your tank and creates a problem for you. Ensuring you have the correct mechanical filtration to remove debris, uneaten food particles and fish waste will help keep the brown algae at bay.

How To Remove Brown Algae From Your Fish Tank

Aquarium Maintenance

If you’ve followed any of our aquarium guides at Pond Planet, then you should understand the importance of regular aquarium maintenance by now. Frequent water changes, gravel cleaning and water testing can help you avoid any major problems before they begin. In this instance, regular water changing will eradicate waste that encourages brown algae growth from the water.

Removing brown algae from your aquarium’s glass

You’ll be happy to know that removing brown algae from your tank’s glass is fairly easy. Using glass cleaning tools as usual, you should be able to wipe it or scrape it away from the glass, returning it to a shiny and clean state. We’d even encourage you to consider magnetic algae cleaners to stop the brown algae making its way further into the tank.

Removing brown algae from your gravel

When cleaning your gravel to remove brown algae, you need to be careful to only clean the top layer of the gravel, as this ensures you don’t remove the good bacteria your gravel can provide to the tank’s wellbeing. 

For small gravel a gravel vacuum is the ideal way to remove brown algae, it’s easy and can remove it quickly. Larger rocks will need to be removed from the tank and hand washed separately, but again this won’t be too difficult to do.

How To Stop Brown Algae From Returning to Your Tank

If you’ve followed our steps and done everything you can to get rid of brown algae from your tank, then the thought of its return may be giving you nightmares. Thankfully, there are a few steps you can take to help keep brown algae at bay:

• Prevent brown algae regrowth through keeping an eye on your tank’s nitrate levels; using water testing kits regularly will keep you on top of this and help you to act quickly if levels alter.
• Assess your tank’s lighting situation; consider adding more and understand the effects of this on your tank’s inhabitants.
• Maintenance, maintenance, maintenance; keeping on top of your tank’s cleanliness can ensure you have everything in place to avoid brown algae making it its home. Regular water changes, glass cleaning and gravel vacuuming will ensure easy brown algae removal is part of your regular routine.

Don’t let brown algae take over your tank. Keep on top of your regular aquarium maintenance with any of our handy aquarium maintenance tools and help prevent it from having the time to get comfy or follow our steps to get rid of it and keep it gone. Most aquarium owners have to face a battle with brown algae at least once, so don’t be downhearted if you do, just follow our steps and your tank will be as good as new!