Deposits
If your household water contains minerals such as calcium and magnesium, repeated splashes can leave behind mineral deposits.
Over time, these deposits can build up and create a yellowish or chalky-looking ring.
Everyday Residue
Small amounts of bathroom residue can accumulate around the toilet, particularly in areas that aren’t cleaned regularly.
Over time, moisture, minerals, and organic residue can combine into a stubborn film.
Cleaning Product Buildup
Another surprising possibility is residue from cleaning products.
Some products can leave behind a film when they’re used excessively or aren’t rinsed
