Hair algae

Hair algae grows on aquarium bottom such as gravel, driftwoods or slow-growing plants. It can grow up to water's surface, strong light will speed up their growth. It usually appears in aquariums which exposed to direct sunlight.

Although this aquarium algae is quite easy to remove, you shouldn't let it bloom by exposing the aquarium with strong light. Poor circulation can also speed up their growth, you should make proper circulation thus it will clump them and keep down their growth.  

Algae eaters like guppy, platty, angelfish or barbs s.a. Puntius family love to eat this hair algae.