How To Stop Algae From Growing In A Fish Tank

Nick Durante
by Nick Durante
Credit: Shutterstock / Olexgood

The sight of algae in a fish tank is enough to make anyone go into panic mode. This can be intimidating, but it doesn’t mean that your fish are doomed. Many people understandably struggle with how to stop algae from growing in a fish tank.

The best way to stop algae from growing in a fish tank is to turn the lights off after 6-12 hours. Remove algae right away when you see it and regularly scrub the rocks and glass in the tank. Change 10%-25% of the water in your tank up to twice each month to stop algae growth.

Make sure to install a filter and avoid overfeeding your fish. Otherwise, uneaten food will increase the nitrate levels in your tank. Follow along as we explore how to stop algae from growing in your fish tank.

How To Stop Algae Growth In A Fish Tank

Whether it be feeding habits or the filter you choose, several simple steps can stop algae from growing in a fish tank. Don’t beat yourself up if you let some algae slide through a few times. This happens to many people. Luckily, we have a few simple tips to help you stop algae growth in a fish tank, such as:

1. Avoid Direct Sunlight

Is your fish tank in front of a window? While that can be visually appealing, it can also help algae grow in the tank. Excessive sunlight can increase the water temperature and make it easier for algae to grow.

This affects fish health even if algae doesn’t grow, as the temperature may exceed 75-80 degrees. That can impact the oxygen levels, appetite, and breathing habits of your fish.

2. Don’t Overfeed Your Fish

Overfeeding can cause algae to grow, as uneaten food sits on the floor of the tank. The phosphate levels in the tank will increase when the food sits at the bottom. Look into the dietary needs of the species of fish in your tank.

There’s a good chance that the fish in your tank don’t need nearly as much food as you think. Remove any uneaten food in the tank after 5-10 minutes. You only need to feed most types of fish 2-3 times per day to stop algae from growing.

3. Remove Algae Immediately

It’s normal to notice a little bit of algae in your fish tank occasionally. However, you must remove it right away to stop algae growth from spreading. Scrub the glass and rocks to get rid of algae blooms before it’s too late.

In extreme cases, you may even need to replace entire sections of the substrate. Some people even vacuum sections of their tanks to stop algae growth. Keep in mind that you must use a special vacuum to safely clean an aquarium.

4. Keep The Water Clean

Changing the water is the most important part of fish tank maintenance, especially if you must stop algae from growing. Replace 10%-25% of the water in your tank once every 2-4 weeks, or as needed if you see algae.

Avoid changing 50% of the water in your tank, as it can greatly disrupt the fish and the healthy bacteria levels. This is one of the best ways to stop algae growth, and changing the water can also keep your fish happy. Algae grows and spreads much faster when the water is dirty.

5. Turn Off The Lights

It’s all too easy to assume you should leave the light in your tank on all day, but you shouldn't. Not only does it affect the day-to-night cycle of your fish, but it can also help algae grow. Fish tanks only need up to 12 hours of light per day, but they often need less.

Some people turn the lights off after only 6-8 hours, and that’s fine too. Excessive light will help create the perfect conditions for algae to grow. This will affect the cleanliness and oxygen levels in your tank, and it can be hard to control.

6. Install A Great Filter

Your fish tank is vulnerable to disease, parasites, and algae if you don’t have a filter. There’s no reason to skimp and buy a cheap filter if you want to protect your fish. Great filters typically cost under $100 and they are easy to install.

Run the filter 24/7 for the best results. Otherwise, your fish tank can quickly become murky and prone to algae growth. Canister filters are among the best options, and they are easy to maintain. You also won’t have to worry about loud operation.

7. Use Plants

While fake plants look great, they won’t stop algae from growing in a fish tank. You can stop algae growth with live plants, however, it’s not that simple. Ideally, you should keep more than 2 live plants in your tank to prevent algae growth in your tank.

This will protect against algae and also add oxygen to your tank. Java moss, guppy grass, and Anubias are among the best plants for a fish tank. They are all easy to take care of and work wonders to keep algae out of your tank.

Make sure to trim your plants as often as possible if you notice algae on the leaves. Otherwise, the algae will spread to other parts of the tank that are harder to clean.

8. Choose Fish That Eat Algae

Luckily, you can find plenty of fish that eat algae, and they can stop it from spreading. Black mollies, flying foxes, and Siamese algae eaters are among the best options. That said, you must check to make sure they are compatible with the other fish in your tank.

These fish patrol tanks all day and do the work for you. They will quickly find and eat algae before it can spread. This makes your job easier, and it also protects the other fish in your tank.

9. Avoid Overcrowding

Get ready for algae to grow if you overpopulate your tank with fish. Your tank will contain more fish waste and uneaten food, and that can create algae growth conditions. This will throw off the bio balance within your tank, and algae will thrive.

Maintain a balance of 1 fish per 1-2 gallons of water to keep your tank healthy. Otherwise, algae will thrive, the tank will lack oxygen, and your fish will be unhappy.

Summing It Up

You must keep your fish tank out of direct sunlight and only run the tank lights for 6-12 hours per day to stop algae growth. It also helps to include several live plants and fish that eat algae, such as flying foxes. Install a great filter and change the water in your tank once every 2-4 weeks to stop algae growth.

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Nick Durante
Nick Durante

Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.

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