I haven't posted to the forum before, but I'm going to hop in here just to give you a heads up, in case you are making the same mistake that I was making in trying to clean up my own swamp, because our experience looks similar. I did 2 weeks of SLAM, really careful to follow all the rules, etc and getting very, very little progress......except, it turns out that my pool was much larger than I knew! I thought I had an 18' round, it turned out I had a 24' round (I never measured it because my husband said 18, I later found out he said that because it "looked like" his childhood pool). Well, that's almost 2x the gallons of water (7600 vs 13,500)! So the little bit of CYA I had put in (to a pool that is all day in the sun) wasn't nearly enough, nor was the 32 gallons of 12% chlorine (not that it would have mattered much with essentially no CYA in the pool). UGH!! Once I realized and redid my calculations, I started making (and am currently still in the process of) real progress.
So, all of this is by way of saying....check your pool size!! Pouring chemicals into a totally wrong size pool is unbelievably frustrating!