Looking for a replacement carbon filter cartridge for 4×21″ housings? This is it. These one-time-use carbon filter cartridges fit the 4×21″ housings from many manufacturers.
Filled with our high-quality activated charcoal carbon, these filters will remove all of the chlorine and chloramines in your water to make it safe for your RO membrane to process.
New carbon filters must be flushed independently of other system components. Just disconnect the outlet tube from your carbon filter housing, point in a safe direction and run for 5 minutes. Black water will exit this tube. After flushing, remove plug and connect hose. You also must flush subsequent replacement carbon filters.
