How to get rid of algae in a fish tank?

How to get rid of algae in a fish tank, its Types and Growth Factors

How to get rid of algae in a fish tank? That is the big question here. Keeping a fish is a quite rewarding and fulfilling hobby, but every valuable thing comes with a price. In the case of this fishkeeping, algae growth is one of the prices.

Algae Growing in your tank can be troublesome for fishkeepers Since most of us begin this hobby with a dream of keeping our aquarium clean. Unfortunately, many of us encounter this annoying algae growth.

Are algae deadly for my fish? Or how come I ended up with algae in my tank? Or how can I get rid of algae in my fish tank?

These are the most common questions asked by most fish hobbyists.

Here in this article, we will answer most of your questions regarding algae growth.

Algae types, their growth factors, and methods to control algae growth will be discussed in this article.

Let’s get started.

Types of algae

Firstly, you need to understand what this alga is? Like plants, algae are another photosynthesizing organism requiring water, oxygen, and nutrients for its growth.

Fortunately, all these things are available in the fish tank. Moreover, the waste of the fish provides the necessary fertilizers for its growth.

Then there comes a time when algae outgrow your plants and start depriving your fish of necessary nutrients.

Although aquarium algae are not practically harmful to your fish, it pollutes the fish tank, makes the water murky and dark-colored, and consumes the essential nutrients necessary for your fish’s growth.

There are many types of algae seen in the natural environment. Following are the types of algae that grow in an aquarium.

Green hair algae

One of the most common algae types, green hair algae, covers the plants, decorations, and aquarium walls in no time. It is parrot green in color with a thin hair-like appearance.

This condition is also referred to as green water condition. The green water can make it difficult for your fish to breathe and even locate its food.

It is not hard to scratch off, but it grows as rapidly as removed. Thus, getting rid of this alga is a never-ending struggle.

Blue-green Aquarium algae

In more clear terms, blue-green algae are not algae but bacteria. Blue-green algae are notorious for their foul smell and slimy appearance. Its sicky nature makes it hard to clean.

It usually grows at the bottom of the tank, covering the whole substrate in a short time.

Brown algae

Brown algae are the commonest type of algae encountered by fish keepers. It gives a dark, dusty appearance to water and hits the main spots like plants and decorations.

Slight variations in water parameters cause the tremendous growth of this algae.

Green spot algae

Green spot algae are dark green in color, and it spreads in the form of spots here and there. As it accumulates a place thus, it is pretty hard to remove or scrape off.

Green water Algae

This alga is the most dangerous one for your fish. As this alga doesn’t spread on glass or decoration, it actually makes your tank water turn greenish.

This polluted water is harmful to your fish as the fish might catch eyesores. It is hardest to eliminate as it requires complete water change.

Staghorn algae

This alga is basically light to dark brown in color. As clear through its name, staghorn algae spread like the antlers. It has fast growth and gives a bizarre look to your aquarium.

READ  Top 12 Small Freshwater Fish for Nano Aquariums - Updated 2020

Red algae

Quite commonly known as black beard algae BBA. This alga is notorious for its hardness and stubborn nature. It is hard to remove as most algae eaters don’t tend to eat it.

This alga can destroy your tank Within a span of a year or two, so be careful. It is mostly brown or reddish grey in colors, with its strands spreading all across the tank.

Factors contributing to algae growth

Sometimes we wonder what we did wrong that lead to the growth of algae in our aquarium?

The answer is that many different factors contribute to the development and growth of different types of algae.

Following is the list of contributing factors to algae growth.


As we all know, light is essential for photosynthesis, and photosynthesis is essential for plants’ growth. Thus, it is clear that algae can’t grow in the absence of light.

Although our fish doesn’t need light for viewing the objects, we actually provide unnecessary light to our fish.

This extra light becomes the greatest contributing factor to algae formation. In fact, light in the form of direct sunlight is a major factor in an algae bloom.

So, balancing the amount of light exposure to the fish tank can greatly reduce the algae growth rate.


Algae get their nutrients from many different ways, including fish waste, deteriorating plants and debris, and surplus food sources.

More the fish waste, the more the number of nutrients available to algae, and the more is its spread.

Thus, cleaning the tank water with the use of a filter at regular intervals is necessary. Moreover, keeping an eye on the amount of fish feed is also important.

Carbon dioxide

Another important factor for algae formation is the amount of CO2. As a necessary ingredient of photosynthesis, CO2 is inevitable for the growth of algae.

As the fish respires, it releases CO2 into the surrounding environment.

Plants take up this CO2 for their growth. Unfortunately, due to algae’s formation, this CO2 is consumed, eventually leading to plants’ wilting and algae’s outgrowth. With the use of proper filter media, we can reduce the impact of CO2.


Warm water aids in algae growth. Most of the freshwater fishes require a temperature between 70-85-degrees Fahrenheits.

To maintain this temperature, most of the aquarium is equipped with water heaters. This increased temperature proves beneficial for the flourishment of algae.

pH and hardness of water

An imbalance in ph level is another factor leading to excessive growth of algae. An ideal range of ph suitable to most of the fishes is 6-7.

The slightly acidic or basic environment can be harmful to fish but can be beneficial for the algae.

Furthermore, water hardness also contributes to algae formation.

Sooner or later, you will realize that water quality is an important parameter for the stability of your aquarium and your fish’s health.

As harder the water, the more minerals it contains, the greater the chances of algae formation and growth. Thus, an efficient water filter can help you combat aquarium algae. Frequent water change can also help in this regard.

Read Our Other Article on How to Remove Hard Water Stains from Aquarium?

How to stop algae growth in aquarium?

To avoid the formation of algae in the first place, you need to remember the following steps while taking care of your aquarium.

READ  What Is New Tank Syndrome? And How to Get Rid Of New Tank Syndrome?

Steps to stop Algae Growth

  1. Avoid excessive light

    Light exposure to your fish tank must not exceed more than 6-7 hours for maximum. Moreover, while selecting your tank’s location, ensure that it is not exposed to direct sunlight.

  2. Regular Water Changes

    Replacing at least 25% of aquarium water every week will remove excess waste from the tank. Furthermore, make sure to clean well using a gravel vacuum to remove any debris or food particle underneath the substrate.

  3. Avoid Overfeeding of fish

    Feed the fish twice a day for not more than 1-2 minutes. The surplus food will decay and ultimately provide nutrients for algae growth and development.

  4. Balance pH level

    Maintaining a correct balance of pH level, water hardness, and water temperature are essential to avoid algae formation.

  5. Efficient Filtration System

    Equipping your tank with an efficient filtration system ensures the maintenance of a clean tank. A clean and healthy aquarium forbids algae growth.

  6. Clean your Gravel and Tank base

    Use water siphons to eliminate any hidden debris and waste of fish food, which might aid in algae formation.

Furthermore, the use of water pumps or an effective aeration system is also compulsory as a significant amount of oxygen can kill off any blooming algae.

As prevention is always better than growth. Thus, the above-mentioned conditions will help you to prevent the formation of algae.

How to get rid of algae in fish tank?

Although algae growth is troublesome and annoying, their removal is not that hard as it may seem. There are many different methods for the removal of unwanted algae from your aquarium.

Use Algae eater

Using Algae eaters is so far the best most natural method to control algae growth. Algae eaters are basically the freshwater fishes that feed on unwanted algae in your tank.

They are herbivores, and their favorite food thus far is algae growing on the walls and decorating your aquarium. By using these Algae eating Fish, you can get rid of this harmful algae.

The most commonly used Algae eaters who are used for algae control are the following.

The list includes fish and invertebrates.

Although all the above-mentioned don’t prey on all types of algae, for example, Siamese algae eaters consume brown algae, and Otocinulus catfish feed on green hair algae.

Thus, the choice of algae is important. Moreover, despite the use of algae-eating fish, there is sometimes surplus algae growth that should be handled with other methods.

How to use Algae cleaner and scrub in aquarium?

Algae cleaners or scrapers are thus far the most time-consuming and effort-taking method, but it is the most satisfying one.

Manually scraping the tank and its component requires the following steps to be followed.

  • First of all, separate your fish and keep them for some time in the holding tanks.
  • Then remove all the equipment from the tank.
  • Now rinse the tank and its ingredients carefully.
  • Use bleach for cleaning the tank. Then use scrapers and blades to scrape off all the algae and dirt.
  • Then again, use the bleach with the help of a brush and carefully clean all the decorations equipment.
  • Rinse all the stuff thoroughly to make sure the tank is free of any harmful chemicals.
  • Now fill the tank with clean filtered water and check the parameters.
  • Setup the tank again and add your fish.
READ  How to raise pH in Aquarium Water? All you need to know.

Oxygen supply

Another method used by fish keepers to remove excess algae is to use liquid oxygen as it is a known fact that oxygen makes the algae starve to death. Thus, the use of liquid oxygen is an effective step to get rid of algae.

In the aquariums that are blooming with a tremendous number of algae, directly add liquid oxygen to the tank and wait for a while.

Afterward, replace the maximum amount of water from the tank and use a gravel vacuum or siphon for better cleaning.


Just like using pesticides and insecticides for killing annoying pests and insects, there are different types of algaecides available to destroy undesired algae.

A wide variety of these algaecides are available for every type of known algae.

These algaecides are available in liquid, gaseous, or the form of pellets. In addition to destroying the algae, these algaecides also pose a serious threat to the plants and fish health.

Thus, one must not use algaecides more than one or two times.

Ultraviolet sterilization

One of the advanced methods of destroying undesired algae is the use of UV sterilizers. These sterilizers can even kill a tiny amount of algae bloom.

Thus, they are quite effective.

One of the most favorable things about using these sterilizers is that they are harmless to fish, plants, and other aquatic life. So, UV sterilizers are your ultimate solution to the algae problem.

Frequently Asked Questions (FAQs)

In case we missed any important point, we have compiled a bunch of FAQs for our readers.

How can I get rid of algae in my fish tank naturally?

Algae can prove very harmful for your fish as it hinders the growth of fish and can lead to the spreading of several diseases as well.
Thus, the following steps can help you get rid of aquarium algae easily.

1. Avoid excessive light especially direct sunlight.
2. Avoid overfeeding your fish.
3. Use Algae eaters to remove the preformed algae.
4. Regular water changes, water filtration, and aeration are necessary.
5. Adequate oxygen supply avoids algae formation.

Will vinegar kill algae in fish tank?

Surprisingly enough a simple household item like vinegar can do wonders when it comes to aquarium cleaning. Every fish keeper must have experienced the problem of excessive algae growth and whitish streaks on aquarium wall.
One simple and quick product to rescue is white distilled vinegar. A set of aquarium scrubs, some table salt and a few ounces of vinegar can help get rid of aquariums algae and hard water stains as well.

Can LED light leads to excessive algae growth?

Any form of excessive light can leads to an increase in the rate of algae growth. As light is necessary for photosynthesis; and photosynthesis can cause algae to bloom.
Thus, LED light can enhance algae production, but it’s not more significant than any other light source. So, LED light is not proven to increase algae growth more than any other light source specifically.


Algae growth is one of the most irritating problems you might face while keeping an aquarium. After getting rid of algae for the first time doesn’t mean that it can’t grow again.

To prevent algae outgrowth, try to maintain appropriate water parameters.

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.