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Do Mollies Eat Algae ? ( Everything You Need To Know )

It is natural to have some algae in every healthy water system. But, they become a nuisance when they outgrow your aquarium. Therefore, many aquarists keep algae eating fish to keep control of algae growth in their aquarium. But, Do mollies eat algae ? Of course, they do. But, they might not be the best algae eaters out there that can solve your algae problem.

Is there any importance of mollies in your aquarium? Do they control algae growth, and if not, what fish would be the best for your algae problem. Let’s talk about this topic in this article.

Do Mollies Eat Algae

Do mollies eat algae?

Yes. Mollies eat algae as part of their diet.

Mollies are omnivorous fish that eat both plant matter and meat matter. Besides algae, they frequently consume small fish, invertebrates, insects, worms, and some plant matter.

Do mollies eat algae in your aquarium?

Yes, they might help you with your aquarium algae problem but will not completely solve it.

Mollies are efficient algae eaters for your aquarium, but many other fish can be better than them to keep an aquarium free of algae.

Mollies are not very effective in controlling algae when they cohabit with other types of fish. But when kept alone in a tank, mollies become good algae eaters.

Can molly survive on algae?

You might think that not feeding your mollies will urge them to eat all the algae in your aquarium so that you’ll have an algae-free aquarium.

While this might work for some extent, will your mollies cope with that?

Since mollies are omnivore fish, they require some protein and fat in their diet, which algae can not provide.

Although your fish will satisfy their hunger with algae, they don’t get all the nutrition they need from algae.

So, No. They can not survive on algae alone, and you will have to feed them with nutritious food for their optimum health.

Do mollies eat algae wafers?

Yes. They do, and they love to eat algae wafers.

As mollies are voracious eaters that always stay hungry, they appreciate every piece of food they get in their surroundings.

Since algae wafers are made out of algae, which is a part of their natural diet, they will readily accept algae wafers as their food.

Do mollies eat hair algae?

Yes. Mollies can eat hair algae too.

But, they might not be very efficient in eating hair algae as these types of algae grow fast and spread across your aquarium very quickly. What’s more, it will be difficult for your mollies to control the spread of hair algae as they grow in length too.

Do mollies eat black beard algae?

Yes, they do. But they need to be very hungry to turn into black beard algae to eat.

Otherwise, they will ignore black beard algae as they are not part of their usual diet. So, if you want your molly to eat black beard algae, you would have to starve your fish for several days.

Do mollies eat green hair algae?

Since green hair algae mostly grow on the leaves of the plants, they are easy to access.

Mollies can easily reach the leaves of plants, so they feed on green hair algae without much problem. In fact, they are efficient green hair algae eaters.

Do mollies eat brown algae?

Yes. If brown algae have grown within their reach, mollies will eat them too.

As brown algae grow on the bottom of your aquarium, mollies might not be able to reach there easily. But if it grows on the leaves of plants, they will munch it up quickly.

Do mollies eat blue-green algae?

Yes. Mollies do eat blue-green algae, but they are not efficient at getting rid of blue-green algae.

Blue-green algae is not an alga, but a bacteria called cyanobacteria. When it starts to grow in your aquarium, it can be difficult to get rid of them.

Are algae good or bad for the aquarium?

Algae is an aquatic plant that grows on wet surfaces.

Algae can photosynthesize to produce oxygen, and they consume oxygen at night. Some algae are desirable in the aquarium as they help filter water and provide food for fish to eat.

On the other hand, large quantities of algae can eliminate beneficial aquarium plants and reduce water quality.

In addition, some algae can grow too large for your fish to munch on it. While algae growth, to some extent, is good for the aquarium and its inhabitants, it is important to control the growth of algae if you want your aquarium to live healthily.

Are mollies effective as algae eaters?

Mollies are effective algae eaters when you starve them for some days.

However, they are not effective as algae eaters when they have an ample supply of food available in their surroundings.

Since mollies are voracious eaters, they will happily munch on any green food that they find in their surroundings.

In addition, mollies are sometimes less effective algae eaters when they have an ample supply of algae food available for them. If you want to keep your fish tank free from algae, then mollies are not the best choice as algae eaters.

How do I stop algae growing in my aquarium?

There are two main reasons for algae to grow in a water system; Lots of light and abundant nutrition.

Having these two sources will cause algae blooms in your aquarium. To stop algae from growing in your aquarium, you have to stop giving them a strong supply of light and nutrients.

There are various ways to remove excess algae growth in your aquarium. 

Reduce lighting of your aquarium

If your tank gets sunlight, it will cause faster algae growth. So, make sure that your tank is placed in a location that doesn’t get direct sunlight.

If artificial lights light up your tank, make sure that they are not stronger and keep the aquarium lights on for about 8 to 12 hours a day and no more. You can use a timer to set up lighting without worrying about excess lighting.

Reduce feeding your fish

If you overfeed your fish, the leftover food and your fish’s waste increase phosphate levels of your aquarium. Increased phosphate levels cause algae blooms.

So, you have to reduce feeding your fish. Feed your fish only what they eat within 3 to 5 minutes and promptly remove excess food.

Change water frequently

The most efficient way to keep nutrients in the water under control is to change the water often. You need to change 10% to 25% water every week, depending on the algae growth of your aquarium.

Clean the aquarium and remove algae by hand

You can control algae growth in your tank by removing algae once they show up. You can scrap the glass, remove and scrub the decorations like rocks, etc.

Once you remove the algae, clean the tank by performing a water change. While changing water, vacuum the gravel to remove excess food or waste.

Grow live aquatic plants

When you grow aquatic plants in your aquarium, the plants will absorb nutrients and CO2 from the water. This will leave no room for algae to grow as there will be fewer nutrients and lights due to the plants.

Keep a strong filter system

The best way to keep your aquarium free from algae is by having a strong filter system that can remove excess food and waste from the water.

With a strong filter system, you will keep phosphate levels under control, thus discouraging algae growth.

Keep algae eating fish

Some fish are known to eat more algae than other fish. Keeping these fish in your aquarium helps control algae growth. So, you can keep other algae-eating fish with mollies in your aquarium to prevent algae growth. 

What is the best fish for eating algae?

Some fish and invertebrates are known to eat algae well than mollies.

While it is true that mollies do eat algae, they are not as effective as other fish in controlling the growth of algae. So, you have to keep more algae controlling fish with mollies in your aquarium.

The best fish for eating excess algae are Bristlenose Plecostomus, Otocinclus Catfish, Chinese algae eater, Siamese algae eater, and Twig Catfish.

Although these fish are popular as algae-eating fish, some invertebrates do better at cleaning the tank than these fish.

Some of the best algae eaters are Amano shrimp, Cherry shrimp, Nerite snails, Malaysian trumpet snails, Ramshorn snail, and Gold Inca Snail.

You can keep mollies, and some of these best algae eaters or other fish are known to eat algae well. If you keep all these species in your aquarium, you will not struggle with excess algae in the aquarium.


Although mollies eat algae, mollies are not effective for cleaning up excess algae in your aquariums.

There are countless other fish and invertebrates that eat algae well. So, you have to keep more of these species with mollies in your aquarium if you want to reduce excess algae in your aquarium.

You can get live plants for your aquarium to keep algae growth under control and You can also remove excess algae by manual means when they show up.

You can also reduce feeding your fish to reduce excess nutrients in the water. Then You have to clean the aquarium and gravel regularly to remove excess food and waste from the gravel. You can also control nutrients in your aquarium by performing water changes regularly.

All these steps will help you keep excess algae under control, and your fish will live happily in a clean and algae-free aquarium.

Credit to : Aquarium Co-Op
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About Dr.Chamika

Hello, I'm Dr. Chamika. I am a Researcher in Water quality, Aquatic organisms, and Environmental chemistry. I am a passionate fish keeper, with10 years of experience. My mission is to help other aquarists experience the joy of fish keeping.