In 17 years of opening this 20x40 vinyl pool (guessing around 30k gallons), I've never had as stubborn a problem with clearing the water as this year.
Nothing unusual about the condition of the water when the mesh cover was taken off. Same lake-water brown as always. This time, the water is finally clearer after 2 weeks of running the filter and almost daily liquid chlorine loads. I can see the deep bottom through the murk.

I lost my old "Ben" test kit (don't ask) so using the simple red/yellow walmart special. The PH is mid 7's.

I use 5 gallon jugs of (allegedly) 12.5% liquid chlor, directly in the skimmer. I also use 4 or 5 of the 1-lb granular shocks from whatever store has the best active ratio (53% is the best I have found). I've never used nearly so many gallons of liquid before, but the green tint will not abate. It looks clean in terms of no milkiness.

The bottom is spotless from vacuuming. The only new variables are a new liner last season (new water), and replacement of an old DE filter with a new sand filter. I understand the sand is not the filter medium that DE is, but it seems to do almost nothing while running 24x7. As to the water, since it is fresh, I am trying to add some stabilizer via some pucks I have around, but without the Taylor kit, no way to measure where that is.

As an aside, I wonder if the liquid is being diluted by the pool store and is no longer actually 12.5%. There is no indication other than what the clerk states.