water treatment system to filtrate water to make purified water, mineral water,etc. pretreatment :1) first we draw out tap water by water pump, then ... has strong a physical adsorb ability , could filtrate organics, free residual chlorine, and heavy metal ion .3) Softener and ... ion ,such as calcium, magnesium ion .4) Ultra-filtration and Micro-filtration: use PVDC or macromolecule material , you know , ...