The author has built an aquarium monitoring and alerting system using a Raspberry Pi, InfluxDB, Telegraf, and Grafana. The system tracks key metrics such as filter running status, temperature within acceptable bounds, scheduled tasks, and water flow rate. To collect readings from sensors, the author used scripts that communicate with the sensors via their respective protocols (1-wire for temperature and pulse-based for water flow). These scripts are then written to InfluxDB using Telegraf's InfluxDB_Listener Input Plugin, providing a buffer against downstream failures. The system also includes alerting capabilities in Grafana, which notify the user of anomalies such as extreme temperatures or low water flow rates. The project is relatively inexpensive, with most components being under £10, and can be expanded to include additional probes for monitoring other water quality parameters. However, finding reliable and affordable sensor hardware remains a challenge.