It is suggested that the service life of medical stone should not exceed 3 months.

The substitution limit is: when the medical stone particles are ground into powder by hand.

Brief introduction of medical stone: it is a natural silicate mineral with the scientific name of quartz monzonite. Medical stone is a kind of compound mineral or medicinal stone which is non-toxic and harmless to organisms and has certain biological activity. The main chemical composition of medical stone is inorganic aluminosilicate. It includes silicon dioxide, aluminum oxide, iron oxide, magnesium oxide, calcium oxide, K2O, sodium oxide, titanium dioxide, phosphorus pentoxide, manganese oxide and so on. It also contains all macro elements needed by animals, such as trace elements such as K, Na, Ca, Mg, Cu, Mo and rare earth elements, with about 58 species.

Medical stone function: it can be used for water purification and sewage treatment, and has a strong adsorption effect on bacteria. Natural minerals contained in medical stone are easily released, and oxygen is released from numerous small holes in medical stone. Purify water by absorbing bleaching powder and other toxic substances.