Diluting concrete with water to make it workable

[Haaheo okole puka]

My initial point being that proper vibration will make most common mixes "workable". Any additional hydration should be done after the initial leveling and smoothing unless the truck has made a long journey from the batch plant. I don't believe this is an air entrained lightweight Ferro cement project or some other specialty application requiring air, it sounds to me as if this is a common home construction project and vibrating then becomes necessary be it a pad or form fill application.