I would never, ever, use vinegar on my expensive granite. It's acidic, not safe for granite, and there is no need to use it. If you find the damp Dobie pad doesn't work (but I think it will), there are alkaline cleaners available that are safe for granite, like Granite Gold. The cleaner must be alkaline in order not to etch the stone. Sophie, my water is just slightly hard. Not worthwhile to do a water treatment plan. It would be rare in my city for someone to have whole house water treatment plan to deal with some pesky white spots and mineral deposits that come off with just a bit of elbow grease. I understand that some regions have very hard water, but your recommendation needs to take into account degree.

Folks I have a troublesome issue that seems pretty severe - this is a three-month old quartzite backsplash right above our range, where I cook multiple meals/day. I see that we 'should have' used 511 Porous Plus, and that maybe our fabricators/installers were subpar, and we're thinking that the hood is actually the issue - but what I actually want to know is: How can I solve (or improve?) this situation? And replacing is simply not an option. Thank you!

The stains are probably a mixture of mineral build up and micro scratches in the porcelain finish that gives the minerals a place to hide. Micro scratches are usually caused by over-zealous cleaning with a scouring powder like Ajax or Bon Ami. Don't ever use scouring powder (or a scouring pad) on an enamel sink. Use a cleaner recommended by the sink manufacturer or Bar Keeper's Friend to deep clean a sink. If you do your daily maintenance, deep cleaning should rarely be needed. Remove the mineral stains with an acid cleaner. We see recommendations that vinegar be used, but household vinegar is not in a high enough concentration to work well. Try a cleaner formulated especially for mineral build-up in enamel-ware. Kohler has several. If that does not work, try a pumice scouring bar like Pumie to remove the worst of the staining, then the acid cleaner on the rest. Easy with the pumice bar. You don't want to add to the micro-scratches. Many light strokes are better than a few heaver strokes. If that does not work, we use an auto-body buffer and a mild buffing compound to remove the stains and polish the enamel surface. This eliminates the micro-scratches and restores to surface to a nice shine. Body buffers are cheap - a lot cheaper then new sinks. Pick up a Wen on line at Amazon or a buffer at Harbor Freight for under $30.00. The buffing compound is available at any auto parts store. Look for one formulated for electric buffers. Old enamel was so thick that the surfaces of old sinks and tubs can usually be restored several times. We recommend regular restoration every 100 years or so.

The floors may have a polish or wax on them. Start with ammonia to remove any polish or wax residue. None of the things you mentioned will remove the old wax or polish. Just be careful with ammonia and make sure there is lots of ventilation. You will need to scrub or mop several times at least. You didn't mention the age of the house. The house I grew up in had that type of tiles in a few rooms. I can still remember the smell of ammonia and wax when my mother pulled out the scrubber/buffer/polisher floor machine. It had interchangeable heads for each step.