In today's episode we are going to go over when to replace filters in your reverse osmosis or reverse osmosis deionization system RO/DI. Since long term success with our saltwater aquariums is heavily dependent on using the highest quality water for top off and water changes it is really important that we change out all of the carbon blocks, sediment filters, deionization cartridges and the RO membrane on time. We will discuss how to know when to change these filters , how to pack refillable DI resin cartridges and why some RO filters are better than others. Your reef tank will appreciate the effort : ) Disclaimer