Hello all! Long time listener, first time caller. This is year two with this pool. The pool itself is 20 yrs old. I know the previous owners resurfaced it in 2018. There’s this weird, rough stuff on the stairs, as well as weird discoloration on the bottom. The discolorations look green, and circularish. The a pic of the steps is attached.
It’s not algae, all levels are perfect.
Anyone have any ideas?

It’s not algae, all levels are perfect.
Anyone have any ideas?
