EvilKid;4084916; said:i guess all i know is once i tested cold water with minimal minerals and metals, about room temp with a bit more and hot with the most. this was a drinking water experiment i ran a long time ago as a school project had several controls and those where my results. i don't remember specifics just the fact that the hotter it got the more their was to be found. i was thrown by this too as i thought hot water kills off bacteria their for it must be the cleanest i was wrong
Once water is heated it has more ability to absorb everything. It is where it goes and what it does after it leaves the water heater that affects what is in it. In your typical home the hot water will move through modern pipes and come in contact with copper, nickel, and brass. But how much of those minerals are picked up when the water is moving fast past it is negligible. I have been changing all of my piping to pex, which eliminates a huge amount of that.