Consistency is a quality component. Water quality can vary over time and season. Rainfall, organic loading, dirt load and reservoir height all cause variable water quality. Add varying chlorine or chloramine levels and the changing efficiency of the treatment system, water quality varies. Reverse Osmosis systems remove up to 99+% of dissolved minerals and some organics by passing pressurized water through a semipermeable membrane. RO water will greatly reduce the variability mentioned above. Nutrients are then added to a consistent base water to optimize plant growth.