Distillation vs. Reverse Osmosis: Which Is Better?
No single water treatment technology effectively removes all contaminants, but distillation and reverse osmosis systems are considered two of the most effective treatment methods. Both improve water quality by removing many of the most serious biological, organic, inorganic and chemical contaminants.
Because each technology has its proponents and detractors, we’re offering an objective overview of their capabilities.
Distillers heat water to boiling and capture the steam, which reverts to water as it cools. Because the high level of heat kills bacteria, cysts, viruses and parasites, in-home distillation units are a reliable, highly effective method for removing potential biological contaminants.
As an added benefit, the process removes a wide variety of other contaminants including nitrates, salt, heavy metals, dissolved minerals (calcium, magnesium) and radionuclides.
Distillation itself doesn’t remove all contaminants, but virtually all installed systems incorporate two filtration stages. The carbon pre-filter removes chlorine, sediment and odors before the water is heated. The post-filter removes chloramine, VOCs (volatile organic compounds) and gases released during the boiling process.
Distillation units require electricity to operate, but the cost can be as low as 30 to 50 cents per gallon of processed water.
Reverse osmosis (RO) systems are often touted as the most effective water treatment alternative. Initially developed in the 1950s, RO was perfected in the 1980s as an effective means of removing salt from sea water to make it drinkable. Water is forced through a semi-permeable membrane with extremely fine pores (about 0.0001 micron), which filters a wide variety of suspended contaminants from the water.
RO is also highly effective in removing biological contaminants such as bacteria, viruses, parasites and cysts, along with salt, chloride, chromium, copper and lead. Some but not all systems reduce compounds such arsenic, fluoride, nitrate, radium and sulfate. Most systems feature a combination of pre- and post-filters that help remove chlorine, chloramine and additional contaminants.
RO units use water to wash the membrane, and because that water is channeled down the drain, some view RO units as water-wasters. However, the washing process only occurs when the unit is in use, so in many instances, it’s the rough equivalent of flushing the toilet a few extra times each day.
Both technologies are extremely effective. High quality systems feature high performance pre- and post-filters, so the integrated water treatment process produces water that’s 99% pure. Both come in a range of sizes varying from countertop or point-of-use models to large systems designed to feed multiple faucets.
The end result is consistently superb drinking water that’s free from contaminants. If you’re used to water laden with minerals and dissolved solids, the pure, clean flavor may seem neutral or flat. Your taste buds will quickly adjust and your body will thank you.