Proper sizing of reverse osmosis systems


Who wants to buy a reverse osmosis system for the home, often faces the problem of which plant size he should choose. Proper sizing of the reverse osmosis system is crucial in any case and should be carefully considered. What you should think about, you can read in this post.

Water consumption per person

The first criterion that decides is what the osmosis water should be used for. The applications for the osmosis water are manifold - at the same time, the drinking water from the line is sufficient for many purposes.

It always remains an individual decision, which water needs in the household covered by osmosis water. The most common uses are:

  • Drink
  • Cook
  • in some cases also for washing vegetables
  • for cleaning (because of the better cleaning performance of osmosis water)

Crucial is the estimation of water consumption also in terms of operating costs of the reverse osmosis system in the home. Several small water withdrawals are economically less favorable than a larger withdrawal. The water quality in the household, especially the water hardness, play a role in the selection of the right system and the most favorable sizing.

The size of the reservoir should therefore correspond more or less exactly to the water requirement of a day. In the case of a four-person household, one can roughly expect around 15 liters of water per day in the above-mentioned activities, perhaps even slightly less. So most families will just get there with a storage tank of around 12 liters.

Also, the storage tank should not be too large to prevent the formation of stagnant water and thus the risk of microbial contamination. This risk is often underestimated.

sewage ratio

Wastewater is not "dirty water" in the reverse osmosis plant but can still be used in some sensible ways. The lowest possible wastewater ratio is therefore not always a criterion in the selection and dimensioning considerations of the plant. If in doubt, you should rather choose a higher wastewater ratio.

The wastewater is only slightly more concentrated than the source water. At a wastewater ratio of 1: 5 - ie 5 liters of wastewater per liter of pure water - this concentration is hardly noticeable by about 1/5. You can not just use the water for watering flowers (flowers love high mineral concentrations in general) but also fill up the water of the aquarium with it, if it lives animals that tolerate greater water hardness (such as guppies).

Another useful use would be to use the sewage for the pond or the pool for refilling. For larger plants, and if something technical effort is made, there is also the possibility to use the wastewater for toilet flushing.


Video Board: Reverse Osmosis Installation