Generally, mechanical filtration is not a good choice for the reduction of Fluoride, Nitrates, Sodium or hardness minerals. For these problems Distillation or Reverse Osmosis is recommended. Distillation is a process of filtration by which water is boiled. The water is caused to evaporate. The evaporation is then trapped and cooled.
Distilled water is basically condensation.
Because the water is boiled and then cooled, the water seems to taste somewhat flat. Keep in mind that distillers require maintenance, much like a coffee maker or humidifier. The minerals build up on the heating element and need to be de-scaled. Distillers work with electricity and do build up heat. Reverse Osmosis is a method of filtration by which the water is first mechanically filtered and then the water is pressed through a semi-osmotic membrane.