We flush the toilet, then the water fills, ...when the filling stops there is a very loud bang sound, and the pipes shake, can be heard through out the house. What is this???.

It is water hammer.

A couple of ideas to look at:

1. If you can get to the water pipe that goes to the toilet, make sure it is clamped down securely.

2. You could try and replace the toilet float valve that's in the tank. It may shut too quickly causing the hammer. There may be some out there that a bit softer closing?

3. If all else fails, you may have to install what is called a snubber in the water pipe to absorb that water hammer. Your water supply pressure may be quite high. That contributes to the water hammer.

Close the supply valve a bit.

Close the supply valve? I was going to open it more, for more pressure. Guess not. Will also look into what a supply hammer is.

Will look into the hammer. The supply pipe is solid.

I will check into all your suggestions, thank you.