Compositions and methods for treating a subterranean formation. The compositions can include positively and negatively charged divalent ions and a total dissolved solids concentration between 2000 and 3000 ppm. In some implementations, the composition includes calcium and magnesium ions. In some implementations, the composition includes sodium, chloride, and bicarbonate ions. In some implementations, the composition includes iodide, phosphate, or borate ions, or any combination thereof. Methods for treating the subterranean formation can include flowing a first aqueous solution that includes sodium ions into the subterranean formation and flowing a second aqueous solution that has a lower salinity than the first aqueous solution into the subterranean formation, where the second aqueous solution includes positively charged divalent ions, negatively charged divalent ions, and a total dissolved solids concentration between 2000 and 30000 ppm.