Just bought home with a whoppin big pool with whoppin big problems. I need help with (1) where to begin and (2) how to figure out how much of whatever to use get the water in shape. (I'm not a novice, just experienced on a much smaller IG vinyl lined pool.) the facts and figures:

inground painted concrete, 45,000 gal
pH 7.9
TA 121
Calcium hardness 145
Free CL 0
Total CL 1.0
CYA 8

Yes I have algae, and it is on the march; but although it looked like a farm pond when we took over, I got the water cleared up to where you could see the bottom before the algae took off. Slowly vacuuming the bottom to waste, lots of organic matter and silt. phew

... three weeks ago I said "I ain't afraid o' no swimming pool". now I'm eating those words

Thanks all