Instructions
Replace lava rocks with live rocks. Live rocks aid in the filtration of water, removing nitrates and phosphates, and also have a thin layer of coralline algae, which will help prevent the growth of hair algae.
Limit nitrate and phosphate levels. Algae needs nitrates and phosphates to grow, so depriving the hair algae in your salt water aquarium of these nutrients should stop the algae from growing and force it to die off. The nitrate level should be kept at 10 parts per million (ppm) or less, and the phosphate level should be kept at 0.03 ppm or less. Preferably, both levels should be undetectable.
Siphon water during partial water changes from the bottom of the tank, especially from areas where you notice a buildup of decomposing materials, or detritus. Decomposing materials release nitrates and phosphates into the water. Replace the dirty water with water filtered using reverse osmosis to avoid adding nitrates or phosphates (which are common in tap water) back into the aquarium.
Install a protein skimmer. This will remove nitrate- and phosphate-creating detritus from the water. Only use high-grade carbon in the protein-skimming system and test the carbon with a phosphate kit before using it, as low-grade carbon can release phosphate into the aquarium.
Add live plants to your salt water aquarium. This will give the hair algae competition for the vital nutrients it needs to survive and will leave less nutrients available, limiting its growth.
Adding certain species of fish, hermit crabs, snails and urchins that eat hair algae can help get rid of hair algae in your salt water aquarium. Make sure these algae-eaters are compatible with your aquarium's temperature and pH level, plants and animals, and your needs. Some algae-eaters won't eat hair algae, will eat live plants or might not get along with a certain species of fish. It's a good idea to do thorough research before choosing any algae-eaters and add one at a time to determine the effect on your aquarium.
Reduce feedings or switch to live food only. Live food creates less nitrates and phosphates than other food as the food is usually alive until it's eaten. Dead or dried food and fish flakes only decompose further in the water releasing the nitrates and phosphates hair algae needs to thrive.
Remove hair algae physically. You can twirl the longer strands around the bristles of a toothbrush to remove them or remove the rocks and scrub them.
Reduce the amount of light your aquarium gets. Like other plants, hair algae needs light to grow. Limiting light can help limit its growth. But don't remove light completely, as coral needs light to survive, too.
How to Get Rid of Hair Algae in a Salt Water Aquarium
Hair algae is often gray-green or light green in color and resembles hair growing on an aquarium's coral, rocks and glass. It's an aquarist's worst nightmare, rapidly growing and spreading throughout an aquarium. This hardy algae is difficult to eradicate and is best managed by combining several methods.