What is this!!?

[James.Lafontaine]

I noticed this growing above some guppy grass on my planted tank, does anyone know what this is? Is has duckweed at the surface

 

[TwoHedWlf]

Algae. Green hair algae is the common name...Though, really more of a description.

 

[twentyleagues]

Algae. Green hair algae is the common name...Though, really more of a description.

Yup exactly what it is.

 

[duanes]

I like to let hair algae grow in my sumps, it uses up nitrate as a food source improving water quality.
And when it gets overgrown, I pull off clumps and feed into my omnivores cichlids.
It is very good source of nutrients and fiber.

In the Cenotes of Mexico it is a major part of the diet for mollies, and almost 50% of the diet for the JDs and other omnivores cichlids that are endemic.

 

[Fishnerd360]

It probably came from either too much light, or too much nutrients.