If totally magkaibang brand or milk… Wag nyo po biglain ng palit kasi baka hindi nya inumin… Pwede pong bawasan unti unti yung dati nyang milk then palitan ng new milk… For example if 8 ounces ang titimplahin gawing 7 scoops na lumang milk plus 1 scoop na bago (kung 1 is to 1 ang measurement ha) then after few days pwede mong gawing 6 plus 2 so on and so forth.