One thing I don't see mentioned here is the higher CYA requirements listed in the manuals for SWGs. I have an aqualogic and the owner's manual lists ideal CYA levels between 60-80 PPM. According to the pentair web site they recommend CYA between 50-75 PPM. I've noticed much better chlorine production when my CYA levels are in this range.

Look at page 11 of the owner's manual for you SWG

http://www.pentairpool.com/misc/owne...lor_Owners.pdf