I am currently doing my first ever SLAM on my pool for black algae, and have a few questions.
Would adding polyquat help speed up the process? I began last Wednesday night, getting my pool up to the slam level of 12. I have consistently been getting at least 2ppm FC loss during the night. Through reading on this site tonight, I see I need to consistently add chlorine throughout the day to keep the FC levels at 12 at least, as it has been dropping to about 10.5ppm by nighttime. I am seeing some of the black algae spots are starting to 'shred' and diminish, so I can see there has been some effect.
I have a gunnite/plaster pool that is at least 35 years old, and needs to be replastered, but it is simply not an option at this point. Am I correct in thinking that the SLAM process will be able to get the algae out of the nooks and crannies?
Do I need to take out the pool light for this?
I seem to have two kinds of black spots in my pool; the round black algae spots that are shredding, and smaller spots that are smaller than a pencil eraser, and do not scrape off with a trichlor puck. I have tried. I have attached two pictures of them.
This morning, FC was 13.5ppm, CC was 0; this evening FC was 10.5ppm and CC was 0. I have not tested for anything else since beginning the slam.
Last question; where on this forum do I create my signature with all my pool info?
28K IG plaster, 2HP 2 speed Pentair, cartridge filter 520sq ft, 150 gal/min flow rate Pentair, built 1984, dolphin deluxe 4, master temp 400 heater, spa