Hello I assume the sprayer has a top pump,this has to be removed to get the liquid in (have you a pic of the sprayer) then its pumped up,that spray isnt instant it takes a fee days to work,also the ambient temperature could have bern to warm it dries to quick ,a cloudy day about 10 to 16 degrees is ideal any higher it wont get a chance to work I use to spray a drive for an old man,it would be baking hot like today could not see where I'd been jezza