How to Remove Bathtub Stains (Yellow, Rust, and Soap Scum)

Bathtub stains come from hard water minerals, rust, soap scum, and body oils. Each type responds to different treatments. Here's how to identify and remove every type of bathtub stain.

What You'll Need

• Bar Keepers Friend Soft Cleanser — removes rust, mineral stains, and soap scum from porcelain and fiberglass
• CLR Calcium Lime Rust Remover — dissolves rust and mineral deposits chemically
• Scrubbing Bubbles Bathroom Cleaner — for soap scum and general staining
• Amazon Basics Non-Scratch Sponges
• Baking soda, hydrogen peroxide, white vinegar
• Rubber gloves

Stain-by-Stain Guide

Yellow or Brown Staining (Hard Water / Mineral Deposits)

Cause: Calcium and magnesium from hard water depositing on the tub surface over time.

Best method: Apply CLR to the stained area, let sit 2 minutes, scrub with a non-scratch sponge, rinse thoroughly. For lighter staining, white vinegar soaked on a cloth and left for 30 minutes works well.

Rust Stains (Orange/Red)

Cause: Iron in the water supply or rust from metal fixtures dripping onto the tub surface.

Best method: Apply Bar Keepers Friend paste to the rust stain, let sit 5–10 minutes, scrub with a non-scratch sponge. For stubborn rust, CLR is more effective — apply, let sit 2 minutes, scrub, rinse.

Soap Scum (White/Grey Film)

Cause: Reaction between soap and hard water minerals that leaves a sticky film on the tub surface.

Best method: Spray Scrubbing Bubbles over the affected area, let foam for 3–5 minutes, scrub with a non-scratch sponge. For heavy buildup, apply undiluted white vinegar, let sit 30 minutes, then scrub.

Dark Stains or Mold (Black/Green)

Cause: Mold and mildew growing in the grout lines, caulk, and corners of the tub.

Best method: Apply undiluted white vinegar or hydrogen peroxide to the affected area, let sit 30 minutes, scrub with a stiff brush. For severe mold in caulk, the caulk may need to be removed and replaced.

Body Oil and Grime (Yellowish Ring)

Cause: Body oils, lotions, and bath products leaving a residue at the waterline.

Best method: Apply dish soap directly to the ring, let sit 5 minutes, scrub with a non-scratch sponge. Baking soda paste also works well as a gentle abrasive.

Frequently Asked Questions

How do I remove old, set-in bathtub stains?

For old mineral stains: CLR or an overnight white vinegar soak. For old rust: Bar Keepers Friend paste left for 15–20 minutes. For old soap scum: Scrubbing Bubbles left for 10–15 minutes before scrubbing. Repeat treatments may be needed.

Can I use bleach on bathtub stains?

Bleach works on organic stains (mold, mildew) but not on mineral deposits or rust. Avoid bleach on acrylic and fiberglass tubs — it can cause yellowing and surface damage.

How do I prevent bathtub stains?

Rinse the tub after every use, wipe dry to prevent mineral deposits, and clean weekly. A squeegee after bathing removes most of the water that causes mineral staining.