How to Get Rid of Green Hair Algae

How to Get Rid of Green Hair AlgaeGreen hair algae is a very common type of algae that a lot of reef keepers will encounter at some point in their early years of their newly set up saltwater tank. Learning how to get rid of green hair algae is fairly simple. All you need to do is understand what causes green hair algae and how to avoid it.

Reasons for Green Hair Algae

The two main reasons for green hair algae growth is phosphates and an incorrect light schedule. Phosphates will normally enter your tank through the use of tap water and an overuse of food. If you used tap water to clean your sand or rocks without rinsing them in RO/DI water, you will most likely have phosphates leaching into your tank leading to a green hair problem.


Overfeeding your tank is another way phosphates can leach into your tank. If you realize that some of the fish food isn’t being eaten, reduce the feedings, as the extra food can cause an increase in phosphates leading to a green hair algae problem in the near future. In my opinion, flake food tends to break into pieces a lot faster than any other type of fish food out there, which is why I feed pellet fish food. You do not want flake food spreading throughout your entire tank before your fish can even eat it. This will be a huge phosphate issue. If you feed flake food, try switching to a pellet fish food like New Life Spectrum. Another type of food that is a cause for phosphates is frozen foods. If you feed frozen foods, you should always rinse the food properly (draining excess liquid containing phosphates) before feeding to your fish and corals.


The second cause for green hair algae is an incorrect light schedule. If you are doing a 12 hour on/off schedule, that might be your problem. It is recommended to do an 8 hour on and 16 hour off light schedule. Too much light will help your green hair algae thrive.

How to Get Rid of Green Hair Algae Fast

The best way to get rid of green hair algae is  by using API Algaefix Marine. This will help kill your green hair algae (turning it brown, then falling off your rock) within about 4-6 days of dosing. The reason why I love this product is because it kills the entire green hair algae colony in your tank, making sure you don’t forget a piece under a rock you didn’t see. Make sure you have fixed the problem (reduce feedings, use proper water, lower lighting hours) before adding this to your tank. If you don’t, green hair algae will just come back again and you will be right where you started.

How to Remove Green Hair Algae Manually

If you are short on funds, you can easily do a manual removal. Just grab, twist, and pull. Wherever you see green hair algae, just remove it by manually ripping it from its base. You may notice that green hair algae will attach to live rock like superglue and not allow you to rip the base off. If the base stays attached, it will just regrow again. If this is happening, you will need to manually remove the live rock from the aquarium, and brush the green hair algae off the rocks with a hard toothbrush. As this may be time-consuming, it will reduce green hair algae greatly until it is finally gone.

How to Prevent Green Hair Algae

As stated above, you can prevent green hair algae by reducing your feedings, feeding properly, reducing your lighting schedule, and by using RO/DI water. If you have extra funds, I will suggest buying a PhosBan Reactor 150 for your tank. A phosban reactor will help remove phosphates that have been leached into your tank. Make sure you buy an appropriate media and pump to go along with it.


Taking all these steps will help reduce and get rid of green hair algae.

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