There are many materials used to make water tanks. Zhuoyue tests different grades of high density polyethylene, polypropylene and tests the dissolution of these materials.

5 mg of different raw materials were placed in 100 mL of ZYMICRO water (resistivity 18.2 MΩ.cm, TOC < 10 ppb) and the dissolution was tested after 24 hours. It was found that for the dissolution of the ions, several comparative materials were not much different. However, after 3 days, it was found that polypropylene eluted more Cl-, NO3-, SO32-, and Mg2+ than polyethylene.

In terms of organic matter (in TOC ppb), the dissolved TOC content of polyethylene was reduced in three days. This shows that as long as it is carefully cleaned, it is possible to minimize the dissolution of organic matter in the PE tank.

Compared with other materials such as FEP (fluorinated ethylene propylene), PA (polyamide), PU (polyurethane), PE materials have the lowest ion and organic dissolution.