Florida water heater

Maybe its Florida water or not....

We thought it was pressure...thats not it
we thought it was the water flow...thats not it...

So we replaced the elec. water heater....while doing the refitting on the copper pipes I notice the old copper pipes had almost a solid block of black stuff in there and solid white pieces.
Maybe thats the problem... I removed the hot water faucet (brand new last week) and noticed on the stem and screen was covered with this white stuff...so now it seems to be just on the hot water side of all the house faucets including the shower. Im assuming its from the old tank and eventually it will clear up...
Im thinking this white stuff is calcium of a sort so the question is.
What is this stuff?
where does it come from?
Will it eventually clear up?
What can I do about it?

I had a gas water heater in my old house..no problems at all.

The white stuff..if it is a flaky plastic...could be did tube. If the old WH was built approx in the '92 to '97 time frame, check the serial number on the mfg. website. In any event, sounds like you need a lot of flushing.

now thats the question....
I know you can clean and flush out going waste water but how do they do it with the supply water???
Can I do it???

To flush the supply lines, first remove all of the screens in your faucets, then turn the water on. For the water heater, run a hose from the drain bib to a drain, turn off the power source, (Gas or electricity) and open the bib. Remember when you finish, the tank has to be refilled. Turn off the drain bib but leave a hot water faucet open at the far end of the house until water runs freely with no air. Then you can turn the power back on and heat the water. Never apply power to any empty tank.

water heater dip tube

i am late on this problem-i have a 7 yr old rheem with a tube that is breaking up. that has been confirmed. it constantly plugs the low pressure aerators. since i am only one using the tank i have put off replacing it,but the foremost faucet is starting to reduce tha hot water flow. i am looking at replacing the tank or changing the tube. see my remarks on the foremost faucet.

It is an old thread but I figured I would mention that some of those flexible water heater connectors are lined with rubber and over time disinergrate and will cause "black stuff" to appear throughout the water.