Algae is a good thing. It appears you have a very healthy tank. Algae is good food for most fish, a good water filter and under decent control, it's got a pleasing color.
I have some hair algae in my tanks and it looks good. All you need to do is keep the tank water clean with routine water changes, don't feed too much and possibly add a floating plant that will compete with the algae for any excess nutrients in the tank water. I like Hornwort. Brazilian or Common water weed is another that uses extra nitrates in the water.
Don't fret over the small stuff!
"Fear not, my young apprentice. Just change the tank water."