Lemon juice is another natural acid that can dissolve hard water stains. Follow these steps:
Squeeze the juice of one or two fresh lemons into the toilet bowl.
Allow it to sit for 15-30 minutes to break down the stains.
Use a toilet brush to scrub the bowl thoroughly and flush away the residue.
Commercial Cleaners
There are various commercial cleaners specifically designed to remove hard water stains from toilets. When using these products, always follow the manufacturer’s instructions and take appropriate safety precautions, such as wearing gloves and ensuring proper ventilation. Popular toilet bowl cleaners include Lime-A-Way and CLR (Calcium, Lime, and Rust Remover).
Pumice Stone
A pumice stone is a handy tool for tackling tough toilet stains. Here’s how to use it safely:
Wet the pumice stone and gently scrub the stained areas. Make sure to keep the stone and the toilet bowl wet to prevent scratching.
Continue scrubbing until the stains are gone.
Flush the toilet and rinse the pumice stone thoroughly.
Toilet Bowl Brush and Elbow Grease
Sometimes, old-fashioned elbow grease is the most effective method. Use a good-quality toilet brush and vigorously scrub the stains. Be patient and persistent, as it may take some time and effort to remove stubborn hard water deposits.

Preventive Measures
Preventing hard water stains is as important as removing them. Consider installing a water softener in your home to reduce the mineral content in your water supply. Regular cleaning and maintenance can also help prevent stains from building up.