How to Get Rid of Green Hair Algae in Your Aquarium

Saltwater and freshwater tanks can easily become infested with green hair algae. While this is primarily an aesthetic problem, the long tangles can strangle your invertebrates and fish. Removal isn’t always easy, but there are methods that can help.

Ultimately, the best thing to do is to prevent green hair algae from growing. We’re going to discuss what it is, why it forms, and how to treat it effectively. Then, at the end, you can learn how to prevent it from coming back so that your tank looks great.

What Is Green Hair Algae?

Green hair algae form long strings. Therefore, it takes on a hairy appearance. Sometimes, people call it string algae, but it’s the same thing.

You can find different species of green algae, and they all use that hair-like appearance. Typically, this algae is a nuisance and isn’t toxic to your invertebrates or fish. However, if you get thick mats of it, invertebrates and fish can get entangled.

This means they can’t eat and could die. Some fish varieties have fewer scales, such as the Koi species. Green hair algae can cut the fish’s skin, which could cause an infection.

Ultimately, you are going to know if you’ve got any type of algae in the tank. It usually starts as a small patch and begins forming long hairs. These algae develop slowly and link up their individual cells into long chains.

Therefore, it might take a long time to notice it. If you leave it alone, the strands of ‘hair’ can grow many inches long.

The bad thing about green hair algae (and any variety) is that it decreases carbon dioxide within the tank and system and adds more oxygen. When you turn off the tank lights, algae breathe and uses the oxygen in the water.

If you don’t have more oxygen being added through a filter or aerator, the fish might suffocate and die. Too much algae can also drop the tank’s pH level, causing respiratory acidosis. A sudden crash of pH can kill the fish.

Where Does Green Hair Algae Come From?

Unfortunately, every system deals with algae because of the fish and sunlight used. It takes one cell to grow a healthy algae population. Even if a UV sterilizer is used on the water coming in with new fish, it could have a cell stuck to it.

Corals and other invertebrates can’t be sterilized using UV light. Though a proper quarantine could help, it’s not a guarantee.

Fish ultimately breakdown their dietary protein o release ammonia. Biological filtration converts the ammonia to nitrite and then nitrate. The nitrates are used as food by algae and other plants.

When there is more food for the algae, you can expect them to grow faster. It’s possible to remove the nitrates by increasing water changes and doing them more frequently. You should also use a gravel siphon to remove extra debris and food from the tank.

For saltwater tanks, the coral supplements, like phosphates, can also be food for algae. If you don’t have corals in your saltwater tank, use a non-coral mixture to keep phosphates low. Those who have corals and high phosphates may want to use a combination mix to ensure that the corals are happy without producing too much algae growth.

Lighting is something else to consider and can lead to algae growth. If there is more artificial light or sunlight on the tank, algae have more energy to proliferate and grow. It’s best to keep the aquarium out of direct sunlight to prevent algae growth and keep temperatures consistent.

Some people also buy algae and incorporate it into the system because algae are beneficial. However, you’ve got to keep it under control. Otherwise, you run the risk of killing your plants and fish.

Treatment of Green Hair Algae

There are multiple ways to treat green hair algae. Let’s take a look at the top four methods:

1. Remove It Manually

The first thing to do is remove as much of the green hair algae as you can manually. This can be difficult, depending on where it is and how much you have. If the plants have it on them, remove them from the tank to get rid of the algae.

You are likely going to need two hands to remove the green hair algae. One holds the plant while the other pulls it off.

Though you should remove heavily infested plants from the water, you can’t remove every plant. They’re going to be beneficial for killing off the rest of the green hair algae. You can use an algaecide dip, but make sure you read the directions carefully.

It’s also possible to rub the décor items with a soft brush, such as a toothbrush. Use chlorinated, hot water for this step.

2. Water Changes

The next step should be a full water change. Algae forms because there’s a buildup of extra nutrients. Depending on what water you use, freshwater can add more micro-nutrients.

There can be a problem with too-frequent water changes. Algae adapt much more quickly to the surroundings than plants and fish. It’s best to do it regularly so that the inhabitants of the tank get used to it.

You should also be scraping the sides of the tank before the water change. This loosens any green hair algae on the sides so that it gets removed.

3. Add More Carbon Dioxide

If you’re already using a CO2 system, make sure it’s operating correctly and that you’re adding enough. You can change the dosage, but ensure that the amount is safe for your fish and plant life.

In a few weeks, you may notice the green hair algae disappearing. However, if you don’t use a CO2 system, you can add liquid carbon.

It’s not as effective as adding CO2 through a pressurized system, but it can be beneficial. Green hair algae dislike carbon, so you’re going to kill it off and protect your fish.

Just make sure that you’re only adding extra CO2 while there are algae in the tank. Once the algae start to go away, you should lower the dosage so that you don’t poison the fish. While they need some CO2, too much can be deadly.

4. Only Use Distilled Water

You don’t really know what’s in tap water. It could contain heavy metals and phosphates, which green hair algae like. If you can’t or don’t want to test your water supply, choose distilled water.

How to Prevent Green Hair Algae?

Preventing green hair algae growth is the best way to keep it at bay. Watch the phosphate and nitrate levels closely. Make sure you’re doing the right maintenance and use the right salt mix (for saltwater tanks).

Where possible, use a UV sterilizer with the system to kill algae before they come into the tank. Also, make sure you’re using the right lighting settings and don’t keep the tank in direct sunlight.

Be diligent and remove green hair algae when you see it. Use barley extracts and bales to keep algae from forming.

Conclusion

Green hair algae are likely caused by an imbalance of CO2 in your water. Fix this problem to see improvements. If that’s not the case, there are other methods to help you get rid of the algae.

Pay attention to how much food you provide to the inhabitants of the tank and use distilled water for changes. Once you’ve gotten rid of the algae, you can keep it from returning more easily.