The resin replacement cartridges for the CR Spotless DIC-10are easy to install and virtually hassle free. You can change the resin cartridges in less than 5 minutes. Simply unscrew the watertight housings and remove the spent cartridge. Then, put the replacement cartridges inside the tube and reattach it to the body of the unit. Youll receive two 10-inch replacement cartridges that will de-ionize approximately 100 gallons of water.