Brian wrote:
I have a new tub and we are starting to notice small specks of what
looks like rust. Brillo cannot get it off nor any other cleaners we
have tried. How is it possible that we have rust in our plastic tub?
How do you remove it?

You have iron pipes and they're starting to rust. Only real fix is to
replace them with copper or CPVC, depending on whether you
can sweat them without setting the house on fire.