formula and water issues

Tonni • Coty❤️💍 Emmy: 11.08.13💖 Grayson: 09.07.16💙 Grace 11.24.17💖
Okay, I pump for my son but don't get enough to save up. So, I do formula once a day. We have nasty well water and so we buy water or get it from my parents house. The tricky part, making it warm. Has anyone put water into breastmilk storage bags and heated it up with hot water from the faucet like you do breastmilk? I don't wanna use the microwave cause 15 seconds one time can be perfect but 15 seconds the next tine it's too hot. It's just water but it seems kinda smart to use a storage bag to heat the water when needed. Keeping the water on the counter, it's still cold. Heating formula and water on the stove takes waaaaay too long and using the nasty water to heat the bottle wears the bottle out sooner. Did that with my first.