I am new to maintaining a pool and have been trying to better understand what needs to be done to keep the water clear and safe – but still don’t have a strong understanding.
We have a 22,500 gallon in-ground vinyl pool. We have had problems this summer with the chlorine level. The pool temperature (floating thermometer) has been between 90 and 105 degrees (higher temperature after we had the cover closed). The pool has been used infrequently this year and mostly the cover has been closed.
I had a pool store test the water yesterday.
Saturation Index: 0.7
TDS: 1000
CYA: 0
Total Chlorine: 0.5
Free Chlorine: 0
pH: 8.1
Total Alkalinity: 178
Total Hardness: 142

The store suggested that I add 8 pounds of shock and they would run an overnight test to see how much shock is needed to get the pool water balanced. After I put in the shock, white globs appeared in the water, mostly on the surface. The water is mostly clear. This morning the pool store called and said it would need a total of 77 lbs of shock. Another option would be to drain the pool part way add new water, then drain again, and then have the water tested to see how much shock was needed at that point. Can you tell me – are these are best and only options for getting the water balanced and getting the white globs to go away?

My husband is considering purchasing a new pump and filter first because he does not believe the circulation is adequate.