The machine you bought is actually a water purifier. Only simple filtration can remove heavy metals, pesticide and fertilizer residues and some harmful substances in water. The white scale you found is that there are too many calcium and magnesium ions in the raw water, but it can't be removed at all because it doesn't have this function. The water is the same as tap water, but it tastes better.
Multifunctional water machine: the name comes from the fact that the water produced by it is acidic functional water and alkaline functional water, which has more than 60 application functions than ordinary water machines.