Limescale forms from mineral deposits in hard water.

Effective methods:

• White vinegar (soak 30 minutes → scrub)
• Limescale removers (anti-calc products) — read instructions
• High-pressure water for rails
• Glass-specific cleaners for shower doors

Common mistakes:

• Using bleach — ineffective
• Using metal scouring pads — causes scratches
• Mixing chemicals — dangerous