Edge-9 Ionizer Cleaning FilterDirections For Use: 1) Turn off your ionizer and shut off the water supply going to the unit. 2) Locate the filter housing of your ionizer and remove the 2nd Filter. You may want to have a towel handy to collect any residual water that comes out when you remove the filter. 3) Attach the Citric Acid Ionizer Cleaning Cartridge. Do NOT over tighten! 4) Turn on both the power to the ionizer as well as the water supply. 5) Run water through the ionizer