You need actual test results for TDS (total dissolved solids), hardness, pH, iron, manganese, Coliform bacteria, nitrates and sulfates, nitrites and chlorides would be nice.
Be careful of Ecowater. They are usually the most expensive and may not work well for long. You can not buy parts or service from anyone other than the one and only local dealer.
If you want to be independent, you could buy from me or other online dealers and install it yourself or hire a plumber to do it and probably save up to a $1000+.