Is this rust or corrosion? Tried using CLR and scrubbing and it's still there. Just a tenant. Also, what would cause this? Toilet is half a year old : r/Plumbing
How to Clean a Very Stained Toilet Bowl | Homely Ville
How would you suggest cleaning the bottom of my client's toilet. Ive tried CLR, pumice scouring stone with borax, clorox, and scrub off. : r/CleaningTips
How to Clean Mineral Stains From Your Toilet | HowStuffWorks
CLR - How to clean your Toilet Bowl with CLR Calcium, Limescale & Rust Remover - YouTube
How to clean a toilet with CLR Calcium, Lime & Rust Remover & CLR Bath & Kitchen Cleaner - YouTube