Switching Milk (NAN OptiPro HW One - NAN OptiPro One)

Hi mommies, Pano po ba kayo mg switch ng milk? Is it switch agad or parang ina alternate niyo yung milk ni baby? When we switched to Nan HW parang nawala colic niya but I think ung tummy niya upon checking is doing okay na so parang gustu ko na siyang i OptiPro Thank you