This study is based on a family of four, each drinking two quarts of water per day. Replacement frequencies are based on the manufacturers suggested schedule.

(1) - $8.00 pre-filter / $16.00 post-filter / $100.00 membrane
(2) - 6 months / 6 months / 2 years
(3) - $8.00 post-filter / $0.25 per gallon electricity / does not include cost of cleaning solution
(4) - 6 months / $0.25 per gallon electricity