6. Name Hui 5 Kyle 6 Guy 7 Greg 8 Water Sample Source From tap water at Bellfonte, PA. From water fountain 15 ft away from a spring at Bellfonte, PA. From Dasani bottle water. Label states that water is from spring water at Bellfonte, PA. From Dasani bottle water. Label does not state water source. Raw Absorbance from AA Ca: 0.3445 Mg: 0.4173 Ca: 0.3444 Mg: 0.4112 Ca: 0.0130 Mg: 0.1600 Ca: 0.0249 Mg: 0.1054 Calculated Hardness from AA Ca: 71.5ppm Mg: 72.1ppm Total hardness: 144 + 1 ppm Ca: 71.5ppm Mg: 71.0ppm Total hardness: 143 + 1 ppm Ca: 0ppm Mg: 24.8ppm Total hardness: 25 + 1 ppm Ca: 0.8ppm Mg: 14.8ppm Total hardness: 16 + 1 ppm TDS results White circle shape residue. More residue than Ca 2+ solution. White circle shape residue. More residue than Ca 2+ solution. White circle shape residue. Less residue than Ca 2+ solution. White circle shape residue. Less residue than Ca 2+ solution. EDTA titration 220 + 20 ppm 13 + 1grains per gallon 160 + 20 ppm 9 + 1 grains per gallon 40 + 20 ppm 2 + 1 grains per gallon 40 + 20 ppm 2 + 1 grains per gallon Softening by Washing Soda 140 + 20 ppm 140 + 20 ppm 0 ppm 40 + 20 ppm * Softening by Ion Exchange Resin 40 + 20 ppm 0 ppm 0 ppm 60 + 20 ppm *