This study compared the effectiveness of six different filter cartridges as regards removing water hardness, pH changes, conductivity, and calcium and magnesium ion concentrations. Two of these cartridges are standard, two are designed for very hard water due to their enhanced hardness-removal properties, one filter is designed to increase water pH, and one is designed to enrich water with magnesium ions. The test was performed on tap water with a total hardness of 394 mgCaCO3/dm3, pH 7.05, conductivity 731 μS/cm, Mg concentration 16.99 mg/dm3, and Ca concentration 106.24 mg/dm3. A total of 150 dm³ of water was filtered throughout each cartridge, with changes in its physicochemical parameters being analyzed at successive stages of cartridge exploitation. The results showed that the filters were most effective during the initial stage of filtration, and their efficiency gradually decreased as the volume of filtered water increased. Research confirmed that jug filters can effectively reduce water hardness; however, their efficiency is largely dependent on the cartridge’s wear rate.