i would not advise any type's of sugar's in the flushing's,i tried karo syrup a couple of year's ago on a grow that was a few day's from harvest at my friend's insistance,it was catastrophic,it formed a putrid smelling foam in my reservoir and nearly killed off the plant's,the foam i learned later was anerobic bacteria,harmful to human's and plant's,and i had to wash everything with bleach(pump,air wand's,tray's,fill-drain part's)i will never do that again needless to say.i now use additives to enhance the flavor and appearence(gen-hydro,floralicious,grow-bloom).....bonbon