sanitizer solution is a mix of chemical sanitizer and water; the concentration of this mix (amount of sanitizer to water) is critical; too little sanitizer may make the solution weak and useless; too much sanitizer may make the solution strong and unsafe; can leave a bad taste on items or corrode metal; concentration is measured in ppm (parts per million); a test kit can be used to check the concentration of a sanitizer solution (make sure it is made for the sanitizer being used/ available from the chemical manufacturer or supplier); hard water, food bits, and leftover detergent can reduce the solutions effectiveness; change the solution when it looks dirty or its concentration is too low; check concentrations often