The present invention relates to a stabilized water treatment composition, containing (i) an effective amount of a hydrogen peroxide source, (ii) a first stabilizing agent, and (iii) a second stabilizing agent; which is essentially free of any peracid-based compounds, derivatives or salts thereof. A method for the using the stabilized water treatment composition to kill or to inhibit the growth of microorganisms such as gram positive or gram negative bacteria, algae, cyanobacteria, viruses, fungi, mildew, mold or combinations thereof, for various water sources such as streams, ponds, lakes, recirculating water systems, surface water, and any other suitable or desirable water sources is also described.