If you purchased your unit after April 6, 2018, AquaTru is programmed to alert you to change your Pre/Carbon Filter (filter 1-2), the earlier of 600 gallons or 6 months; VOC filter (filter 4), the earlier of 600 gallons or 12 months; and your Reverse Osmosis filter (filter 3), the earlier of 1200 gallons or 24 months (2 years).
If you purchased your units before April 6, 2018, AquaTru is programmed to alert you to change your VOC filter (filter 4) after approximate 600 gallons; your Pre/Carbon Filter (filter 1-2) after approximately 1200 gallons; and your Reverse Osmosis filter (filter 3), after approximately 1200 gallons. Note for optimal performance the Pre/Carbon Filter (filter 1-2) should be changed whenever the Reverse Osmosis filter (filter 3) is changed.