kjmelak
The greaest concern with pouring through a skimmer is if you have a puck feeder and have ever had pucks in the feeder. The problem come from the diffrent types of chloring mixing. I understand bad things can happen (like puck feeder go boom) by mixing diffrent types of chlorine.
Some members here great luck pouring in to the skimmer but being I do have a puck feeder and use it now and then I pour in front of the returns. As watermom mentioned you migh want to get Bleachcalc you can download it here.
Steve