Topic

Pool Stain Guides

Identify the stain before you buy anything. The treatments for the three types are opposites.

3 guides on this topic

Something wrong right now? Work through it in two or three questions

A garden hose feeding a pool through a clear inline cartridge housing clamped to the coping, water running

Water ChemistryGuide

Filling a Pool With Well Water: Metals and Stains

Iron, copper and manganese ride in on the fill water and stain the pool the moment you chlorinate. How to test first, and what a sequestrant cannot do.

5 minUpdated Sep 6, 2026

A greasy brown scum band on pale waterline tile, sharply defined where the water sits, a sponge just touching one end of it

MaintenanceHow-to

Pool Waterline Scum: Why It Comes Back and How to Stop It

That greasy band at the waterline is body oil, sunscreen and dust. Here's how to remove it properly and stop it returning every week.

5 minUpdated Sep 6, 2026

Rust-brown and blue-green stains on pale plaster under clear water

Water ChemistryTroubleshooting

Pool Stains: How to Identify and Remove Every Type

Metal stains, organic stains and scale all look similar and need completely different treatments. Here's how to tell them apart.

5 minUpdated Jul 9, 2026

This topic appears in these sections

Water Chemistry Maintenance