Algae ID????

[Jordan Kutun]

What is this algae and how to stop it

 

[Weikel]

Green hair algae. Feed less. Lower nutrients. Keep nitrates low around 2 , keep phosphates around .03.. up your water changes . Make sure to suck out all waste during your water change.. blow off all your rock work before water changes with a Turkey baster.. up size your cuc never hurts..

Would really help to state your water parameters, husbandry, tank size , stocking etc...

 

[Sallstrom]

Maybe not the same algae, but I would recommend the this thread. My guess is you need to add some more grazers.
https://www.reef2reef.com/threads/algae-id-plz.418749/page-2#post-4899684