A:   The first thing to remember is that what we are trying to remove (mineral deposits) is alkali in regards to pH.  Therefore, need to to neutralize with a product that has an acidic pH.  My favorite is Spartan Foamy Q&A.  It is acidic but also has degreasers for the scum and oil.  It is a registered degreaser. Spartan Foamy Q&A is available in  RTU (Ready-to-use, 12/QT/CS), Gallon (4GL/CS), 5 GL Pal and 55GL Drum.  Click here  for more information on Spartan Foamy Q&A.