The initial stage of whole-house water purification involves substituting traditional plastic filter bottles with a food-grade 304 stainless steel integrated unit. This unit is resilient to water hammer, withstands both high and low temperatures, and is impermeable to light, effectively preventing the growth of algae and the leaching of plasticizers, while also eliminating the risk of bottle explosion. Its high-flow design ensures that multiple bathrooms in a villa can operate simultaneously without experiencing any pressure drop. The system supports seamless switching between stainless steel filter meshes and PP cotton/activated carbon filter cartridges, offering both coarse and fine filtration capabilities. Whether connected in single-stage or multi-stage series, it can replace central water purification equipment, saving valuable space. Additionally, it comes with an impressive 10-year warranty, guaranteeing durability and worry-free use.