Methods and compositions are provided for treating a subterranean formation penetrated by a well. The method includes the steps of: (a) forming a treatment fluid, and (b) introducing the treatment fluid into the well and into contact with the formation. The treatment fluid includes: (1) water; (2) a water-soluble polysaccoharide capable of increasing the viscosity of the water or a water-soluble polysaccharide and a crosslinking agent for the water-soluble polysaccharide; (3) a breaker comprising at least one member selected from the group consisting of a source of chlorite ions and a source of hypochlorite ions; and (4) a breaker moderator comprising at least one member selected from the group consisting of a source of magnesium ions and a source of calcium ions.