How to remove brown algae from aquarium? Here is my strategy!

Anyone who has been following my blog for a while knows that I have a thing for algae – or perhaps better said, against algae.

Today, I’m back with another anti-algae strategy. This time not against black beard algae, green water or hair algae but… brown algae! I will tell you in plain language what causes brown algae in freshwater aquariums, but I will also – and this is much more important – give the answer to the question “how to control, remove and prevent brown algae in your aquarium”.

What are brown algae exactly?

Brown algae in your aquarium can be recognized by the brown deposit layer on your plants, decoration or glass. Sometimes they look like slime, sometimes they look like dust. Brown algae are also called diatoms.

Below you will find a “nice” example of brown algae deposits in an aquarium:

Attention: does it feel very rough and have hairs? Then you are probably dealing with black beard algae instead of brown algae (both can be confused with each other). For beard algae, read my strategy here.

What causes brown algae in a freshwater aquarium?

To keep it short, the cause of brown algae is the excess of waste in the water. Once you cross a certain boundary, you really don’t have to wait long for brown algae to appear. Here are a few examples of how it can happen:

• Overdue maintenance of your aquarium
• A poorly maintained or clogged filter
• Dead fish or rotten leaves
• Digging too much into your aquarium soil

You can already see it coming… just one – or a combination – of the above scenarios is enough to give brown algae a chance due to the accumulation of waste in your tank. The natural balance is disturbed and/or your filter can’t keep up anymore and the first brown spots are already there!

Brown algae when setting up your aquarium

Did you get brown algae 2-3 weeks after setting up your aquarium? That’s perfectly normal!

Your tank is not yet in balance and still needs to “mature”. The plants have to adapt to their new environment and the bacterial culture in your filter and aquarium is in full development. In short: your tank is not yet completely balanced and it is still looking for an equilibrium. I sometimes call this the “awkward phase” of your aquarium. 😀

My advice: in this case, don’t make too many changes in your aquarium, give it a chance to mature sufficiently and just be patient. The algae will go away by themselves. Adjusting all kinds of things all the time will only cause more problems.

How to remove brown algae from your aquarium? Follow this stepwise plan

Does your aquarium suffer from brown algae while it’s not in its start-up phase? Then I have the following step-by-step plan for you to remove brown algae from your aquarium. This plan consists of 3 major parts: removing present algae, giving the plants a boost and then preventing brown algae from coming back.

Step 1 to remove brown algae from an aquarium: deal with waste!

Unfortunately, there is no “brown algae aquarium” magic formula, so you will have to get your hands dirty…

• Rub away the brown algae on the glass using filter wool
• Remove the affected leaves as much as it is safe for the plants
• Clean your hardscape with an old toothbrush
• Don’t forget the back wall, but be careful not to break anything
• Brown algae on plants? Gently rub them off & prune leaves that are too affected

Now that you have removed as much of the brown algae as possible, it is time for a severe water change and a good cleaning of the soil. After manually removing brown algae, you can bet that a lot of the stuff is still floating around in your tank. This is where you need to start siphoning everything off, which is why it is important that you change big part of the water quickly.

You score twice here because not only does your water look much better without those debris, it also contains a bunch of fresh minerals in one go.

Step 2: Give your aquarium plants a health boost

You can almost blindly assume that some of your plants won’t look too good if your tank is troubled by brown algae. Quite often, rotting plants are even the ones causing brown algae. Time for an action plan!

• Get a good plant fertilizer to give your plants a boost of nutrients and minerals, such as my All-in-One
• Perform a CO2 check: is there still CO2 in your aquarium CO2 cylinder? Do you have enough CO2 in your tank (tip: use a drop checker)?
• No CO2 installation? Then add a liquid carbon source, such as EasyCarbo
• Give your plants a pruning session, where and when needed
• Give your tank and your plants (and yourself 😉 ) some time to recover

Also, ensure a sufficient water flow: does the flow reach all plants? This is important to ensure that all nutrients and CO2 reach your plants so that they can grow optimally.

Once you have taken care of your plants, it is time to maintain your filter! You have to clean it once in a while to prevent it from clogging up. If that happens, your filter will not function optimally and less power means less water circulation and therefore less waste processing. And this is exactly one of the causes of brown algae in an aquarium.

Step 2 to remove brown algae from your aquarium: prevent them from coming back!

You’ve noticed it already, removing brown algae is no fun! Now that you’ve made all these efforts to clean up that mess, you’d better take action to prevent brown algae from coming back in the future.

You guessed it, no grand strategies are involved here, but some discipline. What is the ideal maintenance routine to avoid brown algae?

Very regular maintenance

Performing your aquarium maintenance once a week is the absolute minimum! Don’t panic, it doesn’t have to take hours:

• See if any plants need pruning and if there are any traces of algae that you can remove
• Change the water every week and remove waste from the soil
• Check your filter and wipe the glass

Keeping plants in top shape

In addition to the technical stuff, you also have to maintain your plants to keep them in top shape:

• Are you adding new plants? Then take extra care not to disturb the soil too much
  
• Make sure you have a good ratio between light, nutrients and CO2
• Maintain the right level of minerals, with additional aquarium plant fertilizer if needed
• If you don’t already have one and you can afford it, invest in an aquarium CO2 system

Plants are not only decorative, they also have a filtering and waste processing function and they provide more oxygen to the water. Excellent reasons to take good care of them!

Conclusion

Removing brown algae or preventing them in your aquarium is mainly a matter of discipline. With their dirty and slimy looks, brown algae can make your tank look like an impenetrable water landscape in no time, but you can get rid of them quickly with a bit of motivation.

If you stick to your maintenance schedule afterwards, it will all resolve itself 🙂