Just for general knowledge, let me explain how it works.
For concrete and cementious stucco, all the moisture that is required for ultimate strength is contained in the initial mix. Nothing is added by adding more water in neutral conditions. Under conditions that sap the initial moisture (high temps and high winds), then the work needs to be protected or moisture added. Use 75 degrees, 80% humidity and zero winds as your baseline to decide if you need to take steps to add moisture or protect the work from excessive evaporation.
Also realize that you are working to extract the final 20% of design strength and decide if it is required or worth it for the extra effort. Good design dictates a 50% safety factor, and for what we are doing here, the safety factor outside of seismic areas is 80% plus.
