Commercial Dishwashers: Water Softener vs. Reverse Osmosis

When installing commercial dishwashers or a glass washer in a café, bar, restaurant or hotel. One of the first analyses to be carried out to avoid breakdowns is the hardness of the water supplied through the water pipes and which the machine will use to wash and rinse dishes and glasses.

Water hardness, along with the chemical and bacteriological composition of the water. They are the basic indicators of whether a water treatment system should be connected to the dishwasher, and perhaps any system. To ensure that it works properly and at maximum performance.

In professional commercial dishwashers: there are two main water treatment systems: water softener and reverse osmosis system

But what are the differences between a water softener and a reverse osmosis system? How do these two systems work and what are their purposes? Can they coexist?

These are important questions to answer because these two water treatment systems are often thought to be synonymous, or that they perform the same task. In reality, despite having common points, these two technologies are based on different operating principles, and provide different services.

In general, the main difference between a reverse osmosis system and a water softener is that while osmosis filters drinking water, purifying it from any chemicals, making it purer, healthier and safer, the purpose of a water softener is to reduce the hardness of the water.

Water softener: what it is and how it works

By nature, drinking water used for home or public use is not chemically pure because it contains different types of substances: dissolved salts, minerals, organic compounds and glass. In particular, the salts dissolved in water are electrically charged (positively and negatively charged ions) and can be removed through the principle of ion exchange or deionization.

Video explaining how a water softener works

This water softener applies exactly the principle of ion exchange, which can change the amount of mineral salts in drinking water, with the aim of reducing the hardness of the water and thus preventing the formation of limescale deposits. The water softener is optional, whether built-in or external for the full range of hood type dishwashers, while it is external only for all other models of glass washers and under-counter dishwashers.

Limescale, also known as lime, is nothing more than calcium and magnesium salts, which, if present in high concentration in the water, cause problems for both the pipes and all the machines that use water from this water supply system.

Ion exchange removes calcium and magnesium salts from the water, replacing them with sodium salts, to obtain “softened” water. This process is carried out by passing the so-called “hard” water through a series of resins inside the water softener. These resins are “loaded” with sodium chloride, i.e. ordinary table salt. The salt is used as an ion exchanger and regenerator, and is gradually depleted during the process, requiring periodic replenishment with new salt.

Depending on the types of ions exchanged, the resins are called cationic or anionic. To soften water, cationic resins are used, that is, resins that exchange positive ions by binding to calcium (Ca++) and magnesium (Mg++) ions and exchanging them with sodium ions (Na+). Sodium salts are not polluting unlike calcium and magnesium salts.

Reverse osmosis system: what it is and how it works

Reverse osmosis technology allows to improve the chemical, bacteriological and sensory characteristics of water in cases where the main drinking water is of poor quality.

Even if it is potable, in fact, the water can be characterized by the presence of various contaminants such as nitrates, chlorine, herbicides, pesticides, microorganisms, organic pollution and residual pollution.

The reverse osmosis unit when combined with a set of dishwashers and glass washers, pushes the water through a series of semi-permeable membranes, applying a very high pressure to the liquid, generating two solutions. Thus separating the heavily polluted water from the pure water.

Thus, we can define reverse osmosis technology as the most advanced and sophisticated water purification technology thanks to the use of activated carbon filters and sediment filters.

Water softener or reverse osmosis system: which one to choose?

The choice of whether to install a water softener or a reverse osmosis system simply depends on the needs and problems you encounter when installing an appliance such as a professional dishwasher or a glass washer:

• Is the problem hard water with a high concentration of limescale? In this case, the optimal solution is to install an anti-limescale system such as a water softener.
• Is there a pollution problem?
• Is there a high concentration of minerals in the main drinking water? The most effective solution is to install a reverse osmosis system.

In general, these two water treatment systems offer a bar, restaurant, cafeteria or other public place the possibility of significantly improving the quality of the main drinking water. Allowing the professional dishwasher to be safely connected to the water supply. The advantages and differences are as follows:

Water softener:

• It is installed directly before the plumbing system in the water pipes, before any faucet, appliance or machine that uses drinking water
• Produces purified water
• Reduces the possibility of breakdown of machines and equipment connected to the water pipes
• Reduces the presence of limescale deposits and corrosion of the water system pipes
• Reduces the presence of limescale spots and stains when washing and rinsing dishes and glasses
• Reduces the concentration of chlorine and limescale deposits in the water. Making it healthier especially for those who are sensitive or allergic to these two elements

Reverse osmosis system:

• It is installed before commercial dishwashers or glass washer
• Generates pure water with low minerals
• Removes chemicals, bacteria and minerals from the water, improving its quality
• Improves the taste and smell of the water
• Provides high-quality water, ideal for cooking, drinking and dishwashing
• Makes water clear and transparent
• Shinier glasses and cups
• Less use of rinse aid and detergents during dishwashing. The drying time is significantly reduced to about 1 minute and 40 seconds after removing the basket from the appliance.

Read also: Choosing a reverse osmosis system for commercial applications

Ideal solution for water treatment?

Connecting a water purifier, located above the water system, to the reverse osmosis system is the most preferred solution. With this type of system, the accumulation of limescale deposits in the membranes of the osmosis system is avoided. This results in lower energy consumption, higher dishwasher performance and much longer filter life.

CareWater Solutions for Reverse Osmosis Water Treatment

Water Care Corporation offers cylindrical reverse osmosis membranes with stable performance, low pressure operation, high water productivity and high pollution resistance. Through research and development and selection of distinctive products for different membrane applications. Water Care Corporation’s reverse osmosis membrane product series consists of using high-performance compound preparation technology.

Which effectively improves the anti-fouling performance of RO membranes and can treat various water qualities and meet water quality requirements. RO membrane elements from Water Care Corporation are available in 8 inch and 4 inch specifications. They are used in seawater desalination, well water brine treatment and thermal power plant feed water. Preparation of pure water and ultrapure water, sewage treatment. Chemical and petrochemical industry processes, food and beverage processing, municipal project engineering and other fields.