Rust from old handrail

[kozak]

I removed an old handrail and there's a heap of rust under it. From what I gather, the best bet is to use citric acid in a bag and let it sit on top.
How long should it sit there, as in, a couple of hours or overnight? Do I need to adjust the chlorine levels? Or don't bother for a one spot baggie fix?
It's pebblecrete surface.

 

[ajw22]

Citric acid or crushed up Vitamin C tablets in a paste put in a sock. Rubbing the area for a few minutes should lift the stain.

Your FC is fine. The citric or ascorbic acid may consume some of your chlorine so check your level when you are done.

Ascorbic Acid Treatment - Further Reading

www.troublefreepool.com

 

[kozak]

Perfect, will give it a shot and check FC. thank you.