Water filter cartridges whose resin binds the undesirable calcium ions must be replaced after a defined flow volume. Larger cartridge-based water softeners trigger an alarm once the maximum capacity has been reached. As a general rule, an indication of the necessary filter change is only visible or audible in the immediate vicinity of the filter. Remote alarm initiation would remedy this problem. The methods commonly employed up to now for remote reading of flow rates and/or residual filter capacity and remote alarm initiation are unsatisfactory: the costs of implementation via a GSM connection are too high, the app solution via Bluetooth has a range of just a few metres and access to a WLAN gateway is insecure. Remote monitoring of filters via LoRaWAN networks offers an intelligent, cost-effective solution.