Reverse osmosis (RO) is one of the most common ways to make great-tasting drinking water at home. Here's how it works, without the jargon.
The basic idea
Water is pushed through a very fine membrane. Water molecules pass through; most dissolved solids, like salts and minerals, are held back and rinsed down the drain. What comes out the other side is much purer water.
The stages of a typical system
- Sediment pre-filter: catches sand, rust and other particles that could clog the membrane.
- Carbon pre-filter: reduces chlorine and improves taste and odor. It also protects the membrane, since chlorine can damage it.
- RO membrane: the heart of the system, which removes most dissolved solids.
- Storage tank: holds purified water so it's ready when you open the faucet.
- Post-filter: a final polish for taste before the water reaches your glass.
Where it's installed
Most RO systems fit under the kitchen sink and feed a small dedicated faucet. Many can also feed your refrigerator's water and ice maker.
Maintenance
Filters need to be replaced on a schedule, typically every 6–12 months for pre-filters and every few years for the membrane, depending on your water and how much you use. We track your install date and remind you when it's time, so you never have to think about it.
Going a step further: RO plus deionization
Aquathin systems, made in Florida since 1980, use a patented process that adds deionization (DI) after reverse osmosis. The DI stage removes remaining dissolved minerals and salts that pass through the membrane, so several barriers work together for very pure water.
Is RO right for you?
That depends on what's in your water. A free test shows what's there, and we'll recommend only what you need.