Reverse osmosis, distillation and of course evaporation with the resulting rain are the true purifiers of water. All of these processes result in water that contains very little contaminates with reverse osmosis and distillation being purer than rain water because rain water can be contaminated with air pollution where as the RO and distillers remove most of this type of contamination. All these processed result in soft water.
Most of the minerals that our bodies need are obtained from the food we eat, the minerals we obtain from water is a very small amount because the minerals in water are called totally dissolved solids and not readily available to the body. Health experts in general say that it is more important to remove the poisons from the water than to be worried about the minerals that a reverse osmosis system would remove, any mineral shortage can be dealt with in the diet.
Reverse osmosis systems can't take the pepper out of the salt so to speak, so the RO's take just about everything to be sure in treating the poisons.
Bacterial growth in a reverse osmosis system is not usually an issue, the in-coming water supply is normally treated with chlorine or by UV sterilisation which has killed off these things before they reach the RO system. The membrane is about 1000 times too fine for harmful bacteria or Cysts to penetrate the system.
The organic material builds up on the pre-filters and this material is removed when the cartridges are changed, we recommend the pre-filters to be changed at 12 months, if the pre-filters were left too long then this organic material would start to break down, even if the filters were left too long and contaminated the system the membrane would still be too fine to allow any harmful bacteria to enter the system, what would happen is bio-film would coat the membrane and pre-maturely end their service life.