Reverse osmosis - what disadvantages are caused by the technology?


Reverse osmosis has many advantages, especially when used in the home, because it produces very pure water. But there are also some disadvantages that you should definitely consider before purchasing a reverse osmosis system. Which ones are explained here.

Acquisition and maintenance costs

The acquisition costs vary depending on the type and size of the system. They are available for home equipment in a range of around 1,000 EUR. Smaller devices can be significantly cheaper, high-performance devices can also be significantly more expensive.

There are also smaller systems for undertable mounting, which can be used purely for drinking water preparation. Because of possible health drawbacks when drinking osmosis water, these facilities are not considered here.

The maintenance costs for systems arise from the necessary filter change within the system, a change of the membrane and the replacement of the possible pre-filter, which may have individual systems.

Very often, a multi-stage filter system is used, which then further increases the maintenance costs. Any necessary inspections will be added.

The frequency of exchanging filters and membrane (s) depends on the one hand on the water quality on the other hand, on the required amount of water and the device.

resource consumption

The consumption of drinking water (from the line) is very high when operating an osmosis system. Depending on the device type, between 2 and 10 liters of drinking water are required to produce one liter of pure water.

On average, efficient plants are today with good output quality of water (even low water hardness) at about 3 liters of water consumption for a liter of drinking water.

That is, the water consumption in the house triples at least.

How much power is consumed depends on several factors:

  • How often the system has to run
  • of the plant type and the energy efficiency of the plant
  • whether a booster pump is necessary (in most systems a higher outlet pressure is required than is available in most domestic installations)

Electricity consumption is not to be underestimated in the case of household installations located at the house connection.

ecological aspects

A necessary cleaning of the water is controversial in Germany due to the high drinking water quality.

Conversely, a waiver of the purchase of bottled water leads to a very effective relief of the environment, since bottled water has a catastrophic life cycle assessment. The purchase of an osmosis system is thus still more advantageous than the purchase of bottled water despite the high water waste. But both are not optimal.

Adverse health effects

Drinking osmosis water as a health product is more than controversial. The total absence of minerals can lead to a serious loss of minerals, electrolytes and salts in the body. The long-term enjoyment is therefore not recommended.

Risk of retrograde microbial contamination

As with all water filters, there is also a risk of microbial contamination in reverse osmosis systems. In these cases, it is mainly about the so-called 'retrograde contamination', if germs can penetrate from behind into the plant. This concerns above all plants with reservoir.

Tips & Tricks

Many so-called environmental toxins are not harmful to health in slight traces. Removal therefore only represents cosmetics. The risk of true bioaccumulation exists only with very few substances.


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