How to remove residue from baby bottles?

Samir

I bought some new bpa free bottles. dr. Brown and some playtex bottles and I boil them and for some reason they have some white powder residue I think it’s from the water. How can I remove this? I want something safe for my baby she is a premature baby and Some ppl been telling me to soak them in Clorox but I’m scared to use it on my baby’s bottles. An advance thanks 🙏