When the Flippin’ Frog flips over the chlorine cartridge is empty and must be replaced. To remove, rotate the two cartridges until the arrows align along the edge of both cartridges and pull apart. If the Flippin’ Frog has not been used for 6 months or one pool season whichever is shorter, simply attach a new chlorine cartridge and set the complete system back in the water. IF the chlorine cartridge still contains a small amount of chlorine after the system has flipped over, place in pool until completely empty. Do not allow chlorine cartridge to sink to the bottom or pool bleaching may occur.