Hard to say how much water we have used it for two months. The resin is good for at least five years. Tank has a five year warranty and head one year. Depending on how much water you use will need regeneration about every two weeks. Regeneration takes about 50 cents worth of table salt and 25 minutes. Where we stay the well water is very hard so we purchased it to help, we are leaving the end of Aug. for the east coast and no longer need it.