Water Filter FAQs

What is Reverse Osmosis?

What is Reverse Osmosis?

Osmosis is when water passes through a membrane (a sheetlike boundary) and other materials cannot pass through or can only pass through in lower amounts. Osmosis happens in all living things naturally, because all life needs water. When water is separated by a membrane, pressure is created by the amount of foreign materials in the water. The pressure will push water from the side of the membrane with less foreign materials until there is a balance between water and foreign particles is equal on both sides.

With some clever science and engineering, osmosis can be made to work for us. We just add pressure, from your home’s water pressure, to the side with more foreign material. The extra pressure can stop or reverse this flow. This means that water will now only flow away from the foreign material. This is Reverse Osmosis.

How Does Reverse Osmosis Work?

In Reverse Osmosis we apply extra pressure to the water to push it through thousands and thousands of membrane layers. The extra pressure stops foreign materials from drawing water to them. The result is these foreign materials are left behind and the only thing that can come through the membrane layers is pure water.

The Reverse Osmosis Membrane is only one stage of our RO Systems; it’s the 4th stage. The 1st stage is a Sediment filter which helps filter things like dirt, sand, dust, and rust. The 2nd and 3rd stages are Carbon Filters which filter things like chlorine, volatile organic chemicals, and odor-causing compounds.

These early stages help extend the life of the Reverse Osmosis Membrane by taking care of many larger coarse contaminants which could damage it. But they do not deal well with Total Dissolved Solids (TDS) which are the most difficult to remove. Ninety-eight percent of TDS are removed by the RO Membrane as well as other difficult contaminants like lead, arsenic, chromium, and radium. The Membrane is where most of the purification takes place.

The 5th stage is a granular-activated carbon filter which does a final pass on your water right before you drink it. This last stage is focused on removing any possible taste or odor in your water. It’s the combination of these stages that’s helped countless customers have water purer than bottled water straight from their faucet.

Express Water Reverse Osmosis Filters

To learn more about the Reverse Osmosis products offered by Express Water, please visit our Reverse Osmosis Systems page.