Treatment fluids and associated methods for treating a subterranean formation. An example method includes introducing a treatment fluid into a wellbore penetrating the subterranean formation. The treatment fluid includes a competitive metal binder selected from the group consisting of polyamino polyether methylene phosphonic acid, hydoxyethylamino-di(methylene phosphonic acid), and a combination thereof; a polymer capable of forming a polymer-metal complex; and an aqueous fluid. The method further includes contacting a metal ion with the treatment fluid after introduction of the treatment fluid into the wellbore and binding the metal ion with the competitive metal binder.