Carbon filtration will not remove dissolved solids (lead, heavy metals) without added ion-exchange resins. RO is generally the most effective broad spectrum treatment method for drinking water.<p>The mineral issue is pretty much bunk, if the lack of trace minerals in your water is a concern you need to see a doctor. Food is your body&#x27;s preferred source of minerals, you have to drink <i>a lot</i> to have much effect on your daily mineral intake.<p>The waste water is real, 4 to 1 is about average, it can be improved but it&#x27;s pretty unavoidable in the process. They are water using appliances, we use 20-40 gallons of water to wash a load of clothes and most people don&#x27;t think twice about it.