Hello everyone...

As I stated in the title, I had green water for 2 days, my pool is above ground and only came with a skimmer/paper filter. its 17'x48" don't remember how many gallons. I shocked with hth Super Shock 'n swim in the morning yesterday, and after a couple of hours it seemed to do nothing, so I consulted a local pool place...

They suggested I get the SandPro Game 1/2 horse filter and to re-shock, which I did, not my water is cloudy white.
I tested it (AquaChek Select) and
the hardness was ok (high end but ok)
the total chlorine is low 0.5 - 1.0,
the free chlorine was low 0.5,
the ph was at the high end of ok 7.8,
the total alkalinity was high between 180-240,
and the Cyanuric Acid was ideal at 30-50

I brushed the floor again this morning it produced a light rust color cloud, flushed the filter although it hadn't gained more than .5 lbs. in pressure, and added shock again to get the chlorine levels back up.

How can I lower the pH and the Alkalinity?
What is making it milky? and how do I get rid of it?