Water treatment dealers looking to sell reverse osmosis (RO) equipment and filters to light commercial and residential customers must keep a few factors in mind when installing and maintaining these popular water treatment options at point-of-use (POU) applications.

As the economy and housing marketing continue to show signs of improvement, customers are becoming more interested and prepared to purchase life-enhancing equipment, such as RO systems. The customer is also able to purchase this equipment from more sources today.

Water treatment dealers can separate their services by knowing which three factors most affect RO’s function and performance. According to experts we interviewed, the three most important factors that greatly affect how a small scale RO system works are:

  1. Pressure
  2. Temperature
  3. Total dissolved solids (TDS)

Many RO units are tested using 70º F water with 300 total dissolved solids (TDS) at 60 psi.

The customer’s water temperature and TDS can impact the effectiveness of the RO system. TDS can slow down the unit’s production and foul the membrane, affecting the taste of the water. The higher the TDS level, the slower the unit will run in order to remove the impurities. Typically, these issues are resolved by adjusting the pressure. However, certain factors will determine incoming pressure, including water in the holding tank.

Of course other contaminants and conditions will affect the performance and lifespan of RO equipment and filters. Pretreatment is important to reduce iron, magnesium or hardness, as examples.

Hardness, above 12 gpg, as well as high levels of TDS will greatly impact the lifespan of the membrane.

Chlorine presents a threat to the RO membrane. Typical RO units feature at least one or two carbon block filters which will eliminate any chlorine from the water before it enters the unit.