After emptying our pool, re-leveling and refilling it this past weekend, we started our Intex SWG last night and ran it for 7 hours, I expected to test the chlorine today and get a reading. When I tested it, there was NO chlorine. Not sure what we did wrong. We did not have CYA in there so we added 2.5 lbs. of it tonight. Is there something else we need to be doing? SWG is on and shows 'working' with no error codes. Advice greatly appreciated!