I am far from an expert on all this stuff. All i can do is offer my experience.
My Harry is blackcherry. I had water spots that i could not get off. Tried different cleansers. Tried using the water softener water instead of straight out of spigot. Different hose nozzles to prevent spots when rinsing. I tried drying immediately. Nothing worked.
Turns out a bit of off hand advice from my forum GTGs (Alcheng and Kenchan) worked. Harry just needed a good clay barring and a really good wax job. Voila'. No more spots. Until my wax gets yucky and thin again anyways. So don't panic just yet.
Just my
