Rusty water in bathtub only

[jjackson74]

I just saw a post similar to the same problems I'm having with Rusty water in my bathtub. Didn't notice it when I first installed the tub. I don't use it that much so not sure why it's like this. It is a jacuzzi tub and my grandson loves to use it when he comes therefore the problem.
The water is dark brownish red not light but dark. When I let it out there's Rusty residue all over the bottom of the tub. I do not have this issue any place else.
I installed copper pipe with the oil rubbed bronze fixtures. It appears the more water that runs in it the darker it gets. Can someone please offer their assistance? Thanks so much for your help.

 

[Reach4]

If there is an access port, look in there for galvanized steel pipes. If you cannot tell by sight, try an extendable magnet.

 

[Sponsor]

 

[FullySprinklered]

Your grandson's name is Rusty?
Sorry, I couldn't resist. There's some iron pipe/fitting in the system somewhere. Surprising how quickly it puts rust into the tub.

 

[Terry]

Are you sure there isn't an old water heater for this bathroom? I don't normally see that much rust if it's in the pipes.