From the Triton II Owners Manual: TR60 uses 325 lbs. of sand or sand/pea gravel for 3.14 sq. ft. of filtering area, 63 gpm flow rate @ 20 gpm/sq. ft. The Sta-Rite P4-R6 pump is 3/4-hp rated. If there's an upload area, I can upload the PDF docs for future reference as I've gathered all of the relevant guides, manuals, etc. for my particular pool configuration.

No idea what the Ca hardness level is by testing, but the annual water report from the SF Public Utilities Commission states the Ca level ranging from 2-26 ppm, with an average of 12 ppm. I've only been chlorinating with Sodium Hypochlorite (Clorox regular bleach in the bulk 1.42 gal. containers from Costco). Never used Ca Hypochlorite in this pool to best of my knowledge.

Today's OTO test results: pH 7.8; alkalinity ~80 ppm; Cl ~6 ppm. Water is still cloudy white but less so than yesterday. Progress seems to be made, albeit quite slowly. Filtration is still being run 12+ hrs. each day for about 1.5 total filtration cycles of the 21K gallon pool.

The links in the replies above don't seem to work for me being a new forum user. If possible, could alternative links be posted that newbies (i.e. me) can access? Many thanks.