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White Algae in Fish Tank: Causes + How to Fix It

White Algae in Fish Tank: Causes + How to Fix It

Fish has been one of the most loved pets around the world! Its low maintenance has increased its demand over the years.

In fact, it is believed by many that watching fish serenely gliding through the water can have a tranquil effect on humans.

However, even though fish are relatively easy to feed and care for, their environment should be appropriately handled.

An unclean aquarium can lead to the growth of white algae, which makes the aquarium appear dirty and can be harmful to your fish in the long run.

In this guide, we’ll talk more about white algae in the fish tank, its causes, and how to fix it.

Also check: How to Get Rid of Hair Algae in Fish Tank

What Is White Algae?

An aquarium can be home to many different algae. The most common being the red and green algae. White algae are considered to be one of the rarest algae.

The white algae are hair-like thin strands found on the surface of objects in the aquarium. White algae are adversely thin, transparent, and white.

Due to this reason, they are very difficult to identify until and unless they grow in large numbers! 

It is important to mention that White algae are often confused with White Fuzz. The latter is a fungus that grows on the driftwood or carcass of a fish left in the tank for a long time. They are more harmful than White Algae. 

White algae grow in freshwater aquariums and do not pose a grave danger to the fish. But, they can be harmful to wounded fish and indirectly impact the fish as its growth is an indicator of unfiltered tank water!


What Causes White Algae in Fish Tanks?

One of the major problems that you will face with White Algae is their rapid growth rate. If they are not controlled in time, they can overtake the whole aquarium or tank within a week.

Therefore getting rid of these algae should be a priority for fish owners. 

Before digging into the remedies for this problem, it is important to learn about the causes. Here are some causes of White algae.

1. Excessive Light

The long duration of the photoperiod contributes to the growth of algae. The algae can be very rapid with their growth and too much much lighting gives them a chance to absorb more. 

Receiving direct sunlight for more than 6 to 9 hours can expedite algae growth.

2. Uneven pH Level

White algae can propagate if the pH level of water is uneven. So, in both cases (either too basic or acidic), algae can grow. 

Keep in mind that the causes of uneven ph levels can include excessive disposal of waste, uncleaned water, and less number of live plants in the tank.   

3. Unchecked Chemicals   

Another cause of algae formation in the fish tank is because of unchecked chemical levels. High levels of phosphate and nitrate in the water can encourage algae growth. 

The uneaten fish food, if left in the water for a long time, decays and produces nitrate and phosphate. These chemicals are found in tap water, so in unfiltered water along with fish feces, and the non-existence of live plants can turn your tank water green!

4. High Levels of Carbon dioxide

The increase in the levels of carbon dioxide takes place when the tank is exposed to light for a longer period. Carbon dioxide accelerates the function of the Rubisco Enzyme present in algae. These enzymes help algae in the process of photosynthesis, leading to their growth.

White algae also use the oxygen present in the water and convert it back into carbon dioxide. Hence, a higher level of CO2 proliferates the growth of white algae.

5. Unfiltered Water 

This is a very important cause to point out. Fish does not just receive nutrition from the food you give. They are aquatic animals which naturally explains the role of water in their survival. Hence, taking care of the water is significant.

Unfiltered water leads to high levels of chemicals that can spike up the population of white algae. Decayed fish food, dead plants, dead fish, etc. can add more to the cause of algae formation in aquariums.

6. Accumulation of Waste

It is logical to understand the benefits of cleanliness. A dirty environment can cause severe illness to human beings. Similarly, an uncleaned aquarium can be harmful to fish!

The debris of dead fish, dead plants, or uncleaned decorative items in the tank is the most suitable place for white algae to grow.

7. Overcrowding of Fish

Overcrowding of fish and other aquatic animals in the aquarium means more food to serve. The more they eat, the more waste they will produce. Therefore, making your tank the perfect place for algae procreation.

Also check: Are Green Algae Good for Fish Tanks?

How Do I Get Rid of White Algae in My Fish Tank?

The growth of white algae may not cause severe harm to your fish in the first week. But once they spread, it can have an indirect impact on the fish that can even cause death. 

Therefore, it is important to get rid of these algae and make the aquarium a safe and healthy space for your fish. 

Let’s look at some of the ways to save your aquarium.

Removing Algae Manually

To remove the white algae manually, you can use a toothbrush or an aquarium scarper. This is a pocket-friendly way to get rid of white algae.

Algae Eaters

Numerous invertebrates and fish can be kept in the aquarium. It is a very easy strategy with no involvement of chemicals and lesser manual involvement. Introducing algae eaters will also add to your aquarium’s diversity.

Given below are the most popular ones:

Amano Shrimps

Amano Shrimps can be your fish’s best friend. They will feed on the white algae. But they can be prey to larger fish. 

Nerite Snails

These nails can be claimed as one the best algae eaters to be kept in your aquarium. They feed on all kinds of algae; green, red, or white. 

The best thing about them is that they cannot procreate in fresh water. Hence, they stick to their job of eating the algae and would not take over the aquarium.

Siamese Algae Eaters

Just like Nerite snails, Siamese eaters also consumes all kind of algae. They will prevent the white algae bloom in your aquarium and keep your pet content.

Maintain Nutrients Level 

Adding live plants can majorly help in maintaining the nutrient level of your aquarium. They will purify the water by breaking down harmful chemicals such as nitrates and phosphate.

Maintaining exposure to excessive light in your aquarium can balance the nutrient content such as oxygen, and CO2.

Removing the decaying food debris, dead plants, and fish can help reduce the production of phosphate and nitrates.  

Change The Filter

A proper filter can make a lot of difference in removing white algae. It will help filter the tap water that contains nitrate and phosphate. 

Also, it will regulate the water cycle and keep your fish tank clean. Hence, allow your aquarium to be free of white algae!

Clean The Tank

Cleanliness is an important aspect when it comes to maintaining an aquarium. Your fish thrives on clean water to survive too. So, try to algae growth by cleaning your fish tank time after time. 

Keep a check on the extra food that you are wasting. Make a point to take them out. Clean the wastes such as feces, dead fishes, dead plants, driftwood, and other decorative items in the tank. 

You should also perform a regular water change. These steps can lessen the growth of white algae.

Rip The Algae Out

Removing white algae is relatively easier than most green algae varieties. You can gently remove them using a hand algae scarper. 

It is important to turn off your filter while dipping your hands in the tank. Once the water is calm. It will enable the algae to be still. It will also prevent the algae from hiding under the objects and growing again. 

Do note that ripping the algae out is a temporary tactic to stop algae growth. 

Siamese Algae Eater

Tips to Prevent White Algae In Fish Tanks

Abiding by the famous saying, “Prevention is better than cure”, let’s go through some of the tips to prevent white algae in a fish tank.

Maintain The Conditions

Maintaining the water condition can be a huge prevention tactic. Hence, you should keep in check the excessive nutrients, the pH value, and light exposure in the aquarium. 

Include Live Plants In The Tank

Welcoming plants do wonders as a preventive method. They provide shade that will limit the penetration of rays into the water which increases the algae growth. 

Moreover, they can also compete with the white algae in the intake of atmospheric oxygen. 

The plants are also helpful in maintaining the pH value of the water. The amount of oxygen released and carbon dioxide intake by plants is always in equilibrium. This maintains the ph value of the water. Therefore, it hinders the white algae bloom.  

Additionally, live plants also make the aquarium seem more vibrant and natural! 

Do Not Overfeed The Fish

As much as over-feeding makes a favorable space for white algae to grow and affects the life of your fish indirectly, it can have a direct effect on their survival too. Many fish can overeat and drown to death. 

The extra food you feed gets wasted and provides nutrients to white algae. Also, the excessive fish food you are wasting is an unnecessary expenditure that you can easily avoid. So, be mindful of it and keep cleaning the fish tank. 

Is White Fungus Harmful to Fish?

White fungus is a white spot attached to the walls of your fish tank or fish tail or other objects in your tank.

There is a high chance of confusing White Fungus and White Algae. This may be because of their white and transparent appearance. Both of them are harmful to fish.

They grow because of dirty water tanks like white algae. A dead plant or fish can hasten its growth as it provides them with more nutrition.

A white algae’s attack can be minor or major depending on how long the water has been tended. They will contaminate the water your fish live in and if your fish is wounded or maybe has a broken fin, the white fungus will attack them.

Does White Algae Mean My Tank Is Cycled?

No, the presence of white algae in your tank does not mean it’s cycled. Since white algae prosper because of the accumulation of waste and imbalanced nutrients in the water tank. It is an indication that the water has not been cycled. 

White Algae in Fish Tank Glass

White algae in fish tank glass are not usual. White Algae needs a substance to stick to and grow. An alga does not have a grip on clean glass. So for the white algae to spread in the fish tank glass the glass has to be dirty. 

Is White Algae Dangerous?

Yes, white algae are dangerous. It has been noticed that the spread of white algae can be quick like wildfire. They can overtake your aquarium which is home to your fish. 

White algae will absorb maximum atmospheric oxygen that will hamper your fish’s blood circulation. 

The growth of white algae is detrimental to the unfavorable water condition of your tank. The unfiltered and dirty water can kill your fish. 

White Algae or Fungus – Difference

White algae and white fungi have some specific differences as discussed below. 


While white algae have a slimy texture, the fungus is powdery, dry, and sponge-like.

Mode of Nutrition 

Algaes are auto-tropic. They make their food through the process of photosynthesis or chemosynthesis. Algaes are non-parasitic.

On the other hand, fungi are heterotropic. They feed on dead animals and plants. Some of the members of the kingdom fungi are parasitic. 


Algae mostly exist in water bodies or places with high moisture content or humidity. White algae can be seen on the plants, glass, or other decorative objects of an aquarium.

Fungus is omnipotent. They can grow anywhere. In an aquarium, they are present on the substrate or gravel.

White Algae in Fish Tank on Wood

White Algae can easily grow on wood. The hard surface of wood provides a favorable surface for algae to grow their root. 

Final Thoughts

Keeping pets can teach a person so much about the essence of love, care, and comfort. Therefore, try your best to make your pets feel safe.

Excessive of anything causes unfavorable consequences. Because of extra food waste, excessive light, nutrients, and dirt, white algae disrupt the peace of an aquarium. 

But if you look deeply for a solution or remedy to the problem you are facing, answers will always come your way. We hope this article answered your call to save your fish today!