At the moment the trade is a wide range of filters and tap water purification systems. We will not consider filter jugs and nozzle on the faucet. Firstly, they clean water surface, and secondly, little expensive to maintain because of the small resource. And as we use compared to bottled water, then consider getting a similar system of water for household use. This is - the reverse osmosis system.
The average service life of the filter for water - 10 years.
During this time, we need to once every six months to replace a cartridge kit, and every 2-3 years is necessary to install a new reverse osmosis membrane.
On average, per day for a family of two people required 5 liters of drinking water (this amount we use in calculating the cost of 1 liter of filtered water), if the family has more than two people, the filter installation is profitable, and the price for 1 liter will be less.
In order to obtain 1 liter of clean drinking water, reverse osmosis system needs 8 liters of ordinary water from the tap.