The two systems
Under-sink RO vs whole home filtration
Echo RO Tankless Reverse Osmosis, $699
Fits under the kitchen sink and pushes water through a reverse osmosis membrane for drinking and cooking water. Tankless means no stored water to go stale and a smaller footprint than tank RO systems. Installs on the cold line with a dedicated faucet; membrane and pre-filters are replaced on a schedule per the manual.
Echo Whole Home Water Filter, $3,499
Installs on the main line where water enters the house and filters every tap, shower and appliance. Sediment and carbon stages reduce chlorine, taste and odor across the home. It is not reverse osmosis, so many households run the RO under the kitchen sink as well for drinking water.