A water conditioning composition includes water; at least one gluconate compound; at least one carbonate compound; a non-ionic preservative; and a phosphate buffer. For example, the composition can include 87-95 wt. % water; 0.5 to 1.5 wt. % gluconate compound; 3 to 8 wt. % carbonate compound; 0.5 to 1.5 wt. % non-ionic preservative; and 0.5 to 2.5 wt. % phosphate buffer.