It is highly recommended that your system is sanitized each year. Just follow these 16 steps*:

1. Turn off incoming flow to the system.
2. Open the faucet where the filtered water comes out (to relieve the pressure).
3. Remove and open the filter housings. Be careful not to spill!
4. Remove cartridges from housing.
5. Remove and rinse the O-ring in the filter housings. Return O-ring to housing. FYI: Some manufacturers recommend replacing O-rings each year.
6. Inspect cartridge for sediment buildup. If high sediment buildup is present it may be time to replace the cartridge.
7. Clean filter housings with warm soapy water and a brush. Also, clean inside the filter housing cap.
8. Prepare sanitizing solution in a clean bucket as follows: 1/3 teaspoon of unscented household bleach for 1 gallon of water.
9. Add 1 cup of the sanitizing solutions to each filter housing. Replace the housing cap (DO NOT replace the cartridge)
10. Replace housing into the system and run the system, letting the housing and system to fill with water.
11. When water starts to flow out of the faucet, close the faucet.
12. Allow water to flow through the housing and system for 30 minutes.
13. After 30 minutes shut-off incoming flow, remove housing(s), and discard sanitizing solution.
14. FYI: Place the carbon block cartridge (with netting) in the first housing, and the KDF/GAS cartridge (with plastic casing) in the second.
15. Replace the housings with cartridges back intot he system, open the valve and allow water to flush the system for five minutes.
16. Close the faucet and check the rates.

*See these steps in action below: