Are you worried about brown algae in your fish tank? No doubt, it looks messy, and it destroys all the beauty of the aquarium. It appears in the form of brown patches or as a thin brown oil layer along the walls of aquariums. In some places, it is known as silica algae.

Once established, it quickly spreads, and it’s tough to control or remove. You will notice that it readily covers the interior surfaces of the aquarium or fish tank. If you are a beginner and you have a new aquarium, get ready. You have to face brown algae.

But don’t worry! After reading this article, you can solve this problem readily. Your tank will look fantastic and be algae-free with a few simple precautions we have discussed below.

Fun Facts About Brown Algae

Brown algae are not algae. It’s a microscopic animal diatom. We advise you not to follow typical algae removal methods to wipe it out. If it’s a microscopic animal, how does it create such vast destruction in fish tanks? 

Numerous tiny Diatoms pile up together, forming a colony that will be visible to you in your aquariums and fish tanks. Surprisingly, you can’t count them because millions of Diatoms combine to form a single brown algae colony.

Are you living in cold environments? If yes, many seaweeds found in cold marine environments will also be part of your brown algae colony, for example, Kelps. According to scientific classification, brown algae belongs to the class Phaeophyceae. 

Important Characteristics of Brown Algae in the Fish Tank 

Here are some characteristics of brown algae that you should know as a fish owner:

• Brown algae are commonly found in freshwater aquariums. 

• Diatoms that make brown algae are single-celled organisms that can exist as solitary cells or in groups called colonies.

• Diatoms convert light into energy, similarly to plants and other algae. 

• Brown algae form an opal-like covering around the cell wall. 

• They look like snowflakes under a microscope. 

• Diatoms of brown algae are non-fragile.

• A pile of Diatoms often protects small water creatures.

Are Brown Algae in Fish Tanks Harmful for Fish?

Brown algae are not harmful to your fish, prawns or snails despite being an eyesore. Even as a snack, several of these species may eat it! However, Diatoms can threaten plants if they are not controlled.

Diatoms from brown algae won’t often hurt your fish as long as you keep them under control. Surprisingly, certain fish enjoy eating these Diatoms, and can aid in tank cleaning. But brown algae are typically not ideal for the home aquarium environment.

Additionally, brown algae don’t adhere to one another, unlike blue-green algae, which can shed in broad, slimy sheets. Diatom patches often detract from the aesthetic attractiveness of your aquarium.

It’s critical to take every precaution to keep brown algae under control.

Important Information: If you leave brown algae uncontrolled, it can be toxic, hazardous, and destructive to the fish and plants in your fish tank. 

How to Discriminate Brown Algae 

Are you confused about brownish patches in your fish tank? Do you want to know how to identify its brown algae or not? Here is the simple solution! In a freshwater tank, you can detect brown algae by its color. If it’s a pure brown color, it’s no doubt Diatoms or brown algae. 

Primarily, it has a mustard or reddish-brown hue. Another important point you may check is a thin brown film over the glass, substrate, or every other surface in the tank. If it’s a yes, be ready to fight against brown algae.

In addition, a small piece of glass feels somewhat gritty when you rub it with your fingertip. Pet owners often confuse cyanobacteria with diatoms. But cyanobacteria easily peel off from a surface than Diatoms.

Diatoms must be removed by rubbing or wiping. And it will just remove the portion you are touching. It doesn’t peel off. Most of the time, strong water current will blow cyanobacteria off.

Causes

Silicates 

Do you want to know about the main brown algal blooms contributor in your fish tank? It is silicate. In simple words, Diatoms love to eat silicates. If you have a high level of silicate in your tank, Diatoms will gladly flourish and replicate there.

Major silicate producers in your tank are:

• Well and piped water
• Salt mixture
• Real rocks
• Real sand
• Play sand 
• Blasting sand 
• Silica-based sand mixtures

Nitrates 

Nitrates are the byproduct of the nitrogen cycle. Decomposing plant material and fish water release ammonia and phosphates. As a result of this process, nitrates are released as a byproduct. At first, ammonia converts into nitrites, then nitrates by helpful microorganisms. 

Diatoms will start to flourish in an aquarium with insufficient plants and high nitrogen levels. These conditions are ideal for brown algae to thrive and cover the surfaces of the tank, substrate and decorations.

Possible nitrate sources in your tank include:

• Well and piped water
• Plant fertilizers
• Fish food
• Dead plant material
• Fish waste

Phosphates 

Phosphates are present in all aquariums. Explicitly, phosphate is a necessary nutrient for all living things, including you. You cannot ban phosphate supply completely in your aquarium because it is a crucial component of life. 

However, excessively high phosphorus levels must contribute to the extensive growth of both Diatom and brown algae. Phosphates are produced when wastes are broken down in aquariums.

• Spoiled fish food
• Plant decomposition waste
• Dying algae
• Fish waste
• KH and pH buffers from dead fish
• Well and piped water 

We advise keeping your aquarium neat and clean to reduce brown algae growth.

Low Light Intensity 

Excessive illumination or high lighting inside fish tanks are mainly responsible for brown algal growth. Just like a bike accelerator, it promotes the colonization of Diatoms. Because of their photosynthetic nature, they thrive well under intense illumination.

Adjusting shallow lights inside a fish tank will support the growth of red and green algae species. Be sure to maintain a moderate light setting for your aquarium. 

Tips to Vanish Brown Algae in Your Fish Tank 

Increase Aquarium Plants 

Are you ready to fight against brown algae? You can achieve the task by simply increasing the number of aquatic plants in your fish tank. We do this to suspend the continuous supply of nutrients to Diatoms.

The Diatoms and plants will compete for vital resources. Plants are primary producers, winning the battle by catching the most nutrients. Ultimately, because of starvation, Diatoms will die or stop their growth. 

You must be alert. Maintain ideal plant survival conditions inside fish tank such as: 

• Enough aquarium LED lighting 
• Nutrient-rich soil 
• Carbon dioxide supply 

Keep Aquarium Clean 

We discussed earlier that high nitrate concentrations support brown algae growth. Now we will share with you the key to reducing the amount of nitrates in the fish tank. It is extremely important to keep your fish tank clean.

It is not a difficult task. You can achieve it with a bit of consistency and hard work: 

• Change tank water weekly. 
• Remove old nitrates and fill the water. 
• Physically clean Diatoms or brown algae. 
• Regular removal of dead or rotting plants. 
• Stop the release of ammonia by waste products. 
• Constantly clear food scraps and fish waste.

Pro Tip: Remember that Diatoms flourish in improperly cycled tanks. To diminish them completely, maintain equilibrium, and make all of the necessary arrangements to ensure your fish tank cycles fast. 

Introduce Reverse Osmosis Water 

Do you know why RO water is best for fish tanks? Reverse osmosis (RO) creates extremely clean water without pollutants, contaminants and nutrients. Now it’s up to you to set the water regeneration parameters you need. 

Combining RO water with tap water is ideal for maintaining a balance during water changes. It helps reduce the water’s nitrate or silica levels. Ultimately, you will be less threatened by the likelihood that brown algae or Diatoms will grow in the aquarium.

Feed Your Fish Less 

Are you conscious about the diet of your fish? Do you provide them with more food than they need? In the aquarium hobby, overfeeding is a common problem, especially for beginners! Are you performing routine maintenance and still notice a lot of brown algae sprouting inside? 

We are sure you are overfeeding your fish which leads to more fish poop. The amount of trash generated by leftover food can result in significant chemical changes in the water. Resultantly, it favors Diatom growth.

Here are some pointers to prevent overfeeding your fish tank: 

• Feed your fish once every 24 hours 
• Always use a vacuum to remove leftover fish food from the aquarium. 
• Include scavengers like loaches, corydoras or nerite snails in the aquarium.  

Boost Water Flow

As discussed earlier, brown algae will stick to surfaces like a sheet tougher. They spread like dust particles by water flow. We advise you to install a water pump that sprinkles water at the aquarium walls to stop this from happening.

The second option is installing a more robust filter to remove patches of brown algae from hidden sides. Critical Alert: Adjust your pump’s water flow according to the tolerance level of your fish.

Include Algae Eaters 

Another great option is the addition of algae eater fish in your fish tank. These fish are also known as Sucker Fish. Having assistance is usually welcome while dealing with severe issues like algae. Fortunately, a variety of fish and invertebrate species are available to take up the battle against brown algae. 

Here is a list of aquatic fish that enjoy eating brown algae and actively help remove Diatoms from the aquarium:

• Bristle-nosed Plecos
• Catfish Otocinclus
• Nerite Snails
• Pest Snails
• Loaches from Hillstream
• Amano Shrimp

Inquire about each species before buying to ensure that it will thrive in the circumstances of your tank.

Keep Ideal Lighting Inside the Tank 

Ensure your aquarium plants receive enough nutrients and light (at least 6–8 hours each day). It’s very critical to compete with the Diatoms. The ideal lighting schedule for planted tanks usually is no longer than 8 hours and no shorter than 6. 

Following these precautions and you can permanently eliminate brown algae. 

Remove the Brown Algae from Your Fish Tank

Seeing brown algae take over your fish tank is very annoying. But the good news is it is simple to handle. You must avoid:

• Rotten water  
• Poor quality aquarium 
• Poot substrates 
• Light and nutrient imbalances 
• Garbage inside the fish tank

However, if your brown algae don’t go away, it’s time to introduce fish or invertebrates that consume algae and use chemical methods. Take a look at the best algae eater fish for your tank. We hope now you learn how to remove brown algae from fish tanks. We wish you the best of luck in fighting against brown algae!