Possible causes: 1) Hard water leading to scale buildup in spray jets. 2) Insufficient water pressure or faulty water heater thermostat. 3) Damaged thermostatic cartridge.

Solutions: 1) Soak and scrub the shower head with vinegar (or replace it with a silicone self-cleaning model). 2) Install a booster pump or check the water heater.

3) Replace the thermostatic cartridge (choose the paraffin temperature-sensing component).

1) Moist oxidation: In constantly humid bathroom environments, metal surfaces exposed to water and oxygen undergo oxidation, leading to rust spots. 2) Detergent-induced corrosion: Using strong acidic or alkaline detergents (e.g., bleach, vinegar) can damage the plating or oxide layer on hardware surfaces. 3) Material issues: Non-304/316 stainless steel or poor-quality plating is more prone to rust, especially in coastal regions with salty air. 4) Residue buildup: Scale, soap, and organic residues react with metal to form corrosive substances. 

Solutions: Mild rust (commonly used household materials)

1) White vinegar + salt: Heat vinegar, soak a cloth, cover rust spots for 10 minutes, and wipe with salt (suitable for stainless steel and copper parts). 2) Lemon juice + salt: Mix lemon juice with salt to wipe. For stubborn rust stains, use foil to scrub (without damaging the plated layer). 3) Baking soda paste: Mix baking soda with water to form a paste, cover rust spots for five minutes, and then wipe clean with a soft cloth. 4) Toothpaste/petroleum jelly: Apply toothpaste to rust spots and lightly brush, or after cleaning rust stains, apply petroleum jelly to prevent oxidation. Stubborn rust (tool assistance is required)

1) Nano sponge + neutral detergent: Dip the sponge in water and lightly wipe. Avoid excessive force to prevent surface damage. 2) Metal polish cream/multi-purpose cleaner: Apply, let it sit for three minutes, and wipe in circles with a soft cloth (test in an inconspicuous area first). 3) Sandpaper (use with caution): Only for non-plated hardware; use 1500-grit or finer sandpaper for light polishing.

Keep dry: Wipe off water stains on hardware surfaces immediately after bathing, and regularly open windows for ventilation.

Pro tip: Though small, bathroom hardware directly affects the comfort and durability of your daily living experience.

When choosing hardware, pay attention to: 1) Material: Copper > 304 stainless steel > Space aluminum > Zinc alloy; 2) Maintenance: Wipe with neutral detergent monthly, and avoid strong acidic and alkaline detergents; 3) Installation: Apply waterproof sealant at drilled areas to extend service life.