Ummm if the roots are just getting offwhite, kinda golden colored, its not root rot. If there is a disgusting rotting potato smell coming from the roots, then that IS root rot. There will be a difference. The golden honey colored roots are normal, they can get like that from the ferts used and then some are just naturally yellowish.
Give it the smell check before you jump to any conclusions, keep ther water temps under 75F and lots of bubbles in the water and it should be alright.