How to Remove Mineral Stains From a Fountain. A common problem with many water fountains is the development of unattractive mineral stains caused by hard water. Layers of pink or white scale form on the surface of the fountain over time, making the fountain look dirty and causing it to run slowly. You can easily treat and prevent mineral stains in fountains with a few common household products and some fountain water treatment.
Consult your fountain instruction manual, if provided, to check for specific instructions regarding types of cleaners that are safe for use on the fountain surfaces. Some fountains have special finishes that can be easily damaged.
Unplug the fountain pump and dump the water out. If the fountain is too large to tip upside down outdoors, use either the drain plug (if there is one) or pump the water out with the fountain pump.
Heat some white household vinegar on the stove until it's just warm (not boiling).
Dip the cleaning rag into the vinegar and lay it on top of the stained area.
Let it sit for 5-10 minutes, to allow the vinegar to loosen up the hard water stains.
Scrub the surface area gently with an old soft-bristled toothbrush to break up the stains. You can use a stiff nylon-bristled brush on durable fountain materials like concrete and cast stone, which can stand up to more vigorous cleaning.
Rinse the fountain thoroughly.
Re-fill your fountain with either distilled water or water treated with a fountain anti-scale product. Both methods will keep mineral stains from developing in your fountain in the future.