Reverse Osmosis vs Distilled Water (RO vs DW)

It is a common thing to drink tap water in order to stay hydrated. On the other hand, it’s true that the water in some cities contains trace amounts of various pollutants, chlorine, pesticides, herbicides, and other dangerous contaminants.

Drinking lead-laced water can cause damage to red blood cells, kidneys, and the brain. Also, it can be dangerous for pregnant women and young children. 

Chemicals that are used to kill bacteria, viruses, parasites, and fungus can be removed by filtering and distilling tap water. There are two advanced ways to do that by choosing distilled and reverse osmosis (RO) types of water.

What is distilled water?

Distilled water is created through the process of distillation. Distilled water is vapor from boiling water that’s been cooled and returned to the liquid state.

This type of demineralized water does not contain any metals, minerals, or even electrolytes. Such an electrolyte-free aquatic organism can be used passively, and it is easily removed from the body together with minerals.

In other words, mentioned type of water is just a well-cooled and collected water vapor.

Distilled water is a type of purified water that is created using a specialized heating process.

Once the water completely vaporizes, that vapor is put into a clean container, where it condenses back into pure water. Distillation is a long process – it requires the storage of water for long periods.

During the process, recontamination occurs from the ambient air and the container, so it requires a lot of equipment to make an efficient result. It is expensive to operate such a process because distillation requires large amounts of water and energy.

Furthermore, a still requires regular cleaning of the boiling pot with hydrochloric acid, sandpaper, and a brush to remove the contaminants which occur during the process.

Pure distilled water is supposed to be neutral with a pH of 7. There are cases then it is with a pH of 5.8 because of the carbon dioxide in the atmosphere, which means that it can be slightly acidic. Furthermore, high concentrations of minerals in soil result that leaves becoming discolored, and the growth of the plants can become stunted.

Watering with distilled water provides an appropriate level of minerals for the soil. Besides, distilled water has a proper amount of indoor plant fertilizer added. In addition, distilled water does not contain fluoride because the water distillation systems that are superior at removing it. 

Water distillation systems remove fluoride and chlorine from the water, biological contaminants (bacteria, viruses, etc.), and other organic/inorganic chemicals, such as fertilizers, hard water minerals, and so on.

Related Topic: How Does Reverse Osmosis Remove Chlorine?

Check Our top picks for water distillers

What is Reverse Osmosis (RO) water?

RO water is nearly pure water with a PH slightly lower than 7. Reverse osmosis is a water filtration method. The water is passed through special membranes which have extremely small pores. The molecules of the water are separated from contaminants and other substances. The water moves through the membrane from a low concentration area to a high concentration area.

The aim of the movement is to equalize the concentrations on both sides of the membrane. The procedure is called osmotic pressure.

The movement of water is influenced by two forces: osmotic pressure and external pressure. The different concentrations of the solutions cause osmotic pressure. When external pressure has been applied, the direction of the solution movement changes – therefore, it is called reverse osmosis. As a result, contaminants remain on one side of the membrane, and purified water flows freely through the membrane.

This method of water filtration is often applied in areas such as the food industry, drinking water, industrial water treatment, wastewater treatment, washing the cars, syrup production, chemical industry, hydrogen production, and so on.

The removal of salts from water by reverse osmosis is based on partitioning the solutions. The solutions are passed through semipermeable membranes. These membranes are permeable to water and retain hydrated ions and molecules of organic compounds.

Salts are removed without changing the water phase. Such permeation is induced by creating a water pressure that is higher than the osmotic pressure. The magnitude of the pressure depends on the salinity of the water.

Such chemical substances as suspended solids, iron, manganese, or chlorine prevent membranes from clogging. Periodic chemical washing of membranes extends their service life. The frequency of membrane washing ranges from three to six months.

In addition, antiscalant is a great chemical solution that prevents the formation of calcium and magnesium bicarbonate deposits on membrane surfaced. Antiscalant has to be dosed continuously to keep the membrane and reverse osmosis water clean.

reverse osmosis filter

Check Our Picks for the best countertop Reverse Osmosis systems.

Also, check my article about the benefits and disadvantages of RO filtration.

What are the similarities between distilled and RO water?

  • Removes 99 % or more of minerals. Such minerals as calcium and magnesium are valuable to their health – distilled and RO water does not contain that.
  • Removes dangerous substances from the tap water (such as chlorine, pesticides, viruses, etc.) Substances that are found in tap water can cause damage to red blood cells, kidneys, and the brain, so it is essential to remove them.
  • Distilled and RO water contains no parasites. Water parasites can cause gastrointestinal issues. For instance, such parasites as cryptosporidium can get into the digestive tract and cause stomach pain. That is crucial for RO water which is considered the type of water that is proper to drink.

What is the main difference between distilled and RO water?

  • Both types of water are made in different ways. RO water is made using filtration methods, and the distilled water is created through the distillation process.

Distilled Water VS. Reverse Osmosis (RO) Water (Distilled vs RO Water)

Although RO water removes a lot of substances, including minerals, it is still appropriate for drinking and cooking. RO water is cleaner and fresher than tap water. Since the water is removed from all impurities, it tastes better and is even better for cooking.

RO water does not contain microbial cysts, heavy metals, and dissolved salts. Reverse osmosis filters are good at filtering such substances as mercury, lead or iron. Moreover, it removes various microbial cysts, which can cause severe illnesses. Such microbial cysts as giardia, cryptosporidium, and cyclospora can be extremely dangerous for health and are usually found in tap water. Thus, reverse osmosis filters can make them disappear.

Related: Does Reverse Osmosis Remove Lead?

Although it is quite expensive, these filters are able to remove a large number of impurities. On the other hand, distilled type of water is just a well-cooled and collected water vapor, which does not contain any useful substances for the body. Distilled water is the best type of water for machinery and batteries.

This type of water does not contain heavy metals, synthetic organic contaminants, asbestos or arsenic. Even though distilled water is completely pure, it cannot remove volatile organic compounds because of a lower boiling point than water.

Thus, distilled water filters can remove pollutants but also necessary minerals.

Related: Can Can Distilled Water Kill You?


This is my blog about the ways and solutions that can help you improve your health by taking more value from drinking water. As improving health means a lot to me, I decided to create the Water On Top project with the purpose to reveal the benefits of water, the finest products to take our daily water to another level, and much more great stuff about water that I believe is on top of our nutrition.

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