I recently embarked on my second SLAM. Everything went great and it was technically over in about 24 hours by the tests for completion. But I had over-shot with FC and got to 21 when I only needed FC 12 minimum. So I just continued the SLAM for good measure with the scrubbing and pump running since I had to wait for the FC to drop to normal levels anyway. The pool has looked superb all this time and we're now down to FC 12 and it's been cold (for here in South Florida) so we cranked up the spa to 103 (my wife loves HOT). It got so hot I had to turn on the bubble pump to cool it off a little. Our bubble system is one of those kind that runs a 1.5 HP pump off the spa and recycles to the spa through venturi's to suck in air. As it cranked up we got a strong whiff of that chlorine odor! How could this be I thought?? I've been chlorinating, SLAMing, and extended SLAMing! Pretty quickly I realized I never turned on the bubble pump unless we're using the spa so organics and any algae cells were in there just lurking. I bet they were having a BIG party down there while I was scrubbing away! When I turned on the pump I think they were instantly chlorinated with 12 ppm FC water and I got the first smell of chloramines I've had from this pool. I've had algae but never any CC and never any chloramine odor. I think the algae level was so low that chloramines formed were completely oxidized immediately. Just when I think I'm getting this pool stuff figured out I learn something new again! Kind of a humbling lesson that I'm still a newbie...
Note to self: turn the bubble pump on a couple of times per week to make sure its pump, piping, strainer get chlorinated too!
I hope this helps somebody avoid my mistake.