Can betta fish eat algae?

In this post, we will answer the question “Can betta fish eat algae?”. We will also discuss if the presence of algae in the tank is beneficial for betta fish.

Can betta fish eat algae?

No, betta fish cannot eat algae. Because they are carnivores rather than omnivores, they are unable to adequately digest algae or plant stuff. Their digestive system is not specialized in metabolizing vegetal matter.

Are algae good in betta fish tanks?

Green algae are one of the most prevalent varieties of algae that you will encounter in any betta tank or aquarium. It is also one of the most difficult to detect. Moreover, in modest doses, it is harmless. However, if it becomes too large, it may become ugly, and you’ll want to get rid of it as soon as possible. Green algae is a kind of algae that may be found in practically any fish tank and are quite prevalent. Its appearance might be slimy, bushy, or hair-like. The good news is that, in the vast majority of situations, it is innocuous.

What are the common causes of green algae in betta tanks?

Normally, there are a few explanations for green algae that are growing out of control or murky green water (cloudy green water can arise in similar settings to green algae). Some of the most prevalent causes of green algae in betta aquariums include the following:

Too much light

Do you have a specific location in mind for your tank? If it’s placed in direct sunlight, it will rapidly transform into the ideal setting for green algae to begin growing and flourishing. 

In addition to this, you should consider whether you are leaving your betta’s lights on for an excessive amount of time. Bettas have a natural circadian rhythm, so as long as they are exposed to 6-8 hours of light every day, they will be perfectly healthy and happy.


For algae to develop uncontrolled, two conditions must be met. Light and nutrition are essential. We’ve previously discussed light as a contributing factor, and the next topic is nutrition. 

When you overload your tank, the fish in it will create waste at a rate that is greater than the rate at which the filter and water changes can remove it. If you overfeed fish, any food that does not get consumed will go to waste. 

You’ll see phosphates and nitrates being released as the waste from both of these sources begins to rot and decompose. This is exactly what algae require to begin growing at a quick pace. 

In addition to decomposing debris and garbage, overstocking the tank will result in higher levels of CO2 being released into the environment. Every time a fish takes a breath, it is exhaling carbon dioxide into the atmosphere. In addition, algae, like other plants, transform CO2 into oxygen.

Infrequent water changes

You should also make sure that you’re changing the water in your tank regularly to prevent the possibility of green algae growing in your aquarium. You are essentially taking away some of the waste materials that algae require to develop when you change the water. 

And the leftover garbage will be diluted with new water to make it safe to dispose of. It is recommended that you do a 10-20 per cent water change once a week or biweekly (depending on the size of your tank) to help limit the likelihood of green algae taking root in your betta tank’s environment.

Not enough cleaning

In addition to irregular water changes, infrequent cleaning is another prevalent reason for clogged drains. Cleaning your tank will not only remove any algae build-up, but it will also remove any nutrients that the algae may have been receiving from the tank’s water.

How to remove green algae from betta tanks?

Green algae, on the other hand, aren’t very difficult to get rid of. You may only want to physically remove it and then remove it again when it returns. Other times, you may need to be more thorough to slow its progression. Whatever your strategy, here are some of the most effective methods for removing green algae from your aquarium.

Removing it manually

Hand removal of algae is one of the quickest and most effective methods available. I’m not referring to just scratching away with your hand, to begin with. However, there is a range of various equipment available to you to assist you in the removal of algae. 

Algae scrubbers and scrapers are specifically made for this purpose, and you can find them for a reasonable price on Amazon. Magnetic scrapers are among the most effective tools you may employ, although long-handled scrapers are equally effective in this situation. 

And if that doesn’t work, you may try using a razor to get rid of any obstinate algae that have accumulated. Just keep in mind that if your tank is acrylic, you should use a plastic razor blade.

Using bleach & hot water

As soon as you’ve eliminated all of the green algae from your tank, it’s time to start thinking about the decorations. If you want to clean your decorations, you should start by taking them out of your tank. Remove them from the water and thoroughly clean them in hot water until all of the algae has been removed. 

It is possible to soak the algae for 20 minutes in a bleach solution if they are persistent or you want to be extra thorough. It is important to use 5 per cent bleach and 95 per cent water when making a bleach solution for cleaning. Following the removal of the algae from your decorations, thoroughly rinse them in water before rinsing them again with conditioned tap water to remove any remaining algae. Remember to avoid putting bleach on natural decorations such as driftwood since they may absorb part of the bleach’s disinfectant properties.

Vacuuming the gravel

After you’ve cleaned the sides of your tank and the decorations in it, you’ll want to vacuum the gravel out of the bottom of the tank. All of the algae that have fallen off the sides will congregate in this location. Once you’ve vacuumed it up, it’ll be gone for all time. 

It’s important to remember that while vacuuming gravel, you want to raise the gravel vacuum slightly above the ground so that you don’t suck up all of the gravel. When using sand, you should increase the gravel vacuum even more, or you may wind up with a tank that is naked in appearance.

Using less light

In addition, throughout the following couple of weeks, reduce the amount of light entering your tank. Reduce the length of time you leave your lights on by 5 to 6 hours every day to conserve energy. This will make it far more difficult for algae to photosynthesize in sufficient quantities to live.

Ultraviolet sterilisers

Investing in a UV steriliser is a wise decision if you want an effective way to eradicate algae from your tank while also benefiting the tank itself. They are reasonably priced, with prices ranging between $10 and $30. They will, on the other hand, be useful in the removal of algae. In addition to germs and other potentially dangerous items in your tank. 

In addition, they resemble the UV rays seen in the sunshine, so you don’t have to be concerned about them inflicting damage to your betta.

Are green algae bad for your betta?

Even if you are aware of how to remove algae, this does not necessarily imply that you should do it. A healthy tank will frequently include green algae, which is an indication of a well-balanced ecology. It is only when the growth of green algae spirals out of control that it becomes a concern for humans. 

It’s not your betta who will be affected; it’s the other plants in the tank who will be affected. However, if you don’t have any plants in your tank, you should think about allowing algae to develop because of the benefits it provides.


In this post, we answered the question “Can betta fish eat algae?”. We also discussed if the presence of algae in the tank is beneficial for betta fish.

If you have any thoughts or doubts, feel free to drop us a comment below!

Frequently Asked Questions (FAQs): Can betta fish eat algae?

What is the best way to get rid of algae in my aquarium? 

If algae grow on the leaves and stems of your aquarium plants, establish a programme for cleaning them consistently. Dip the plants in a solution of 5-10 per cent bleach for a few minutes at a time as needed to kill the algae. If you use bleach, make sure you completely rinse them since it might kill your fish. 

What is the best way to naturally get rid of algae in my fish tank? 

Change the water frequently to keep nutrients low, and if you have plants, use a liquid fertiliser to enhance the plants and aid them in their natural battle against algae. If you don’t have any living plants in the tank, you may use nitrate and phosphate resins to absorb any excess nutrients and starve the algae, which will help to keep the tank clean. 

Is algae in an aquarium a cause for concern? 

The presence and proliferation of algae in an aquarium are not always harmful. It is beneficial. That is the normal course of events. It demonstrates that your aquarium is well-balanced and in good condition. It is only when the algae are allowed to grow out of control and cover the entire surface that it becomes a concern. 

Is it possible for aquarium algae to disappear on its own? 

They normally go away on their own within a few weeks, but it is possible that it could take many months in certain instances. If you want to get rid of brown algae more rapidly, there are certain actions you may do. 

What is it that destroys algae in the natural world? 

Take a brush and some baking soda and get to work. In addition to killing algae and loosening it from the wall, bicarbonate, the active element in baking soda, is an excellent spot treatment for removing it off the wall. Make certain that you have removed every last particle; black algae have very lengthy and tough roots, which makes them a particularly hard strand of algae to remove. 

Do LED lights contribute to the growth of algae? 

Contrary to popular belief, LED aquarium lighting does not promote algae development any more than other types of aquarium lighting. 

Why does the water in my fish tank continually turn green? 

Emergencies of “Green Water” are produced by a rapid expansion of suspended algae, known as phytoplankton, in the water. Green water algae, in contrast to other algae species that grow on the glass or items in the aquarium, float around the tank and multiply by the billions in a short period, a phenomenon known as a “bloom.”


Burgess, W.E., 1989. An atlas of freshwater and marine catfishes. A preliminary survey of the Siluriformes. T.F.H. Publications, Inc., Neptune City, New Jersey (USA). 784 p.

Ferraris, C.J. Jr., 2007. Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types. Zootaxa 1418:1-628.