Disappointing you didn't pass the SLAM, however even if you would've drained some water, the algae would still be in there. The FC drop of about 4 in darkness cannot be ignored. Something still remains. So while you continue to brush & clean the filter, there may be one last issue to consider. While we sound like a broken record at times, double-check any areas algae can hide. If you have a light fixture (niche), look behind it. If you have stairs, look under them or in each rung (step) if they are portable. Look under the poolside skimmer lid. Something if feeding off of your bleach and all that hard work. Bleach (chlorine) is the #1 sanitizer, so hang in there.