It is important that your system be installed properly. The proper sequence is as follows: water source, softener, carbon filter, machine. It is important to install them in this order for two reasons.
First, the carbon filter removes odor, off taste, and bacteria. It also removes chlorine; you don't want to remove chlorine from water before it goes into a softener, or the softener becomes a breeding ground for bacteria. Second, if any of the ion resin becomes loose in the softener cartridge, you don't want it going into your espresso machine. When installed in the proper order, the carbon filter will catch the resin before it can get into your machine.
Your carbon filter should be replaced once a year. It is rated as follows: 500 gallons or 1 year, which ever comes first. You will never go through 500 gallons before one year is up so just remember to change it annually.
How often should you change your softener cartridge? This will vary depending on how hard your water is. There is a formula and it is not difficult. First, you need to know how hard your water is in grains of hardness. The softeners I sell will remove approximately 850 grains of hardness. Simply divide 850 grains by the number of grains of hardness in your water and the answer is how many gallons of water can be softened before it becomes necessary to change your softener cartridge. To monitor the amount of gallons of water going through your machine and insure you change your softener when necessary we recommend you instal this flow meter to measure your water usage, Mavea Flow Meter
What do you do when it's time? First, turn off the water source. Next, make your machine call for water, causing the pump to come on. You must relieve the pressure from the lines or you will not be able to unscrew the housings or disconnect the John Guest Fittings. Once the pump comes on, let it run for no more than 5 seconds and turn it off. Now turn your machine off and disconnect the water line from your machine. Next, unscrew softener housing. Rinse out the housing and put a new softener cartridge in. Place the end of the John Guest tubing into a bucket and turn the water on full blast. Let 2 to 3 gallons of water run through the new softener to purge it and then turn it off. Connect the John Guest tubing back up to your machine and you are set to go.