The WFST can be installed at the cold water inlet of washing machines or dishwashers. It contains an insoluble polyphosphate deposit which protects household appliances from scale buildup. Additionally, it stabilizes iron compounds and prevents rust stains on fixtures. The polyphosphate also gradually dissolves existing scale. Compatible with most dishwashers and washing machines available on the market. The WFST extends the lifespan of household appliances.