What kind of filter is used for water purification machine
Yellow should be a primary pp cotton filtration, which is a bit of rust and silt. The filtration of chloride is adsorbed by secondary active carbon.
The filter is a PP cotton material, and the filter is yellow after a long period of time, not necessarily chloride, which is likely to be silt and rust
It is usually pp cotton, activated carbon, ultrafiltration membrane, and then activated charcoal