Even if you buy perm water, it's no use not knowing the professional operation process. In fact, the key to the quality of potions lies in how professionals control them, so all potions are similar. Generally, the lowest ph value of medicinal liquid is 8 and the highest is 13. The proportion of ph value of medicinal liquid suitable for hair quality is certain. As long as very professional people know. Even some so-called hair stylists are useless. In other words, the ph value can also be adjusted at will. Professional hairdressers don't sell perm water, they sell technology.