3 Ways to Remove Rust Stains From a Concrete Pool

Rub vitamin C tablets directly on light rust stains underwater. The ascorbic acid dissolves surface rust from hairpins or tools in seconds without harsh chemicals.

Use oxalic acid powder for deep orange or brown stains from iron in water. Dissolve it in water, brush it on, let it sit a minute, then scrub and rinse thoroughly.

Avoid muriatic acid unless you are experienced. It can etch concrete if diluted incorrectly, so start with vitamin C first to avoid damage.