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Hard water stains can be tough to remove, but a few products and methods can help. Use a pumice stone to gently scrub the stains without scratching the porcelain. You can also try pouring white vinegar into the bowl and letting it sit for a couple of hours to dissolve the mineral buildup. For persistent stains, a specialized cleaner like Lime-A-Way or The Works Toilet Bowl Cleaner can dissolve the minerals effectively.

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