If the FC started out at 9ppm and it dropped to 5.5ppm FC in just a few hours, then someone did the test wrong or you have low CYA in the water or you have a massive FC demand and you need to continue the SLAM. I understand stopping the SLAM because of scheduling problems but the longer you wait to clear a pool, the more liquid chlorine, time and money you waste.
It's up to you to do what's in your best interest but you need time to focus on SLAMing the pool and keeping it up until you pass the SLAM exit criteria. Starting and stopping a SLAM is not an optimal approach.
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006