Reverse Osmosis filtration systems require annual maintenance in order to perform their best and provide you with the purest possible drinking water. Filters that are not changed annually will result in buildup inside of your Reverse Osmosis system, causing lower overall performance. This can lead to unclean drinking water, as well as faster degradation of the system, R.O. membrane, and internal components. Systems that have not been serviced annually may not be covered under warranty.