Pool idiot needs help getting started

[greenpoolman]

Hi,

I am new to owning a pool and have read some of the stickied introductory posts however I'm totally lost with where to start.

The walls of my pool appear to be growing some kind of algea.

Pics:
https://imgur.com/a/u2TJPrj

I have added chlorine, as well as algeacide. I also tried scrubbing the walls with a brush however it made no difference - the algea doesn't come off.

Could anyone give me any idea what the next steps would be? Add more chlorine and keep scrubbing?

Thanks so much to anyone patient enough to be able to offer some pointers!

[Denniswiseman]

It could be iron staining, are you on a well?
Try rubbing ascorbic acid (Vitamin C) in a sock on it. It can be purchased online