I have a vinyl liner but have very high CYA. I don't have any issues with well water or water table. I've read and read that my option to lower CYA is to drain and refill. I don't think I can really drain 75% of my water because I think that's bad for the liner. So I've planned to do a 25% drain about once a week for about 5 weeks. (Pool is 4 ft across all the way) Trouble is, I've done it twice now and don't seem to be getting anywhere. What am I doing wrong?
Tested 7/14:
FC- keeping around 12
CC- 0
pH- 7.4
AL- 140
CYA- 160
tested 7/19 (after 25% drain/refill)
FC- keeping around 12
CC- 0.2
pH- 7.5
AL- 140
CYA- 160
tested 7/24 (after 25% drain/refill)
FC- brought up to 11
CC- 0.2
pH- 7.5
AL- 150
CYA- 140
Extra info: we just bought the house and I don't know anything about its history other than the buckets of chemicals (pucks) left by the previous owner and the ridiculous green swamp that it was when we took off the cover.
Tested 7/14:
FC- keeping around 12
CC- 0
pH- 7.4
AL- 140
CYA- 160
tested 7/19 (after 25% drain/refill)
FC- keeping around 12
CC- 0.2
pH- 7.5
AL- 140
CYA- 160
tested 7/24 (after 25% drain/refill)
FC- brought up to 11
CC- 0.2
pH- 7.5
AL- 150
CYA- 140
Extra info: we just bought the house and I don't know anything about its history other than the buckets of chemicals (pucks) left by the previous owner and the ridiculous green swamp that it was when we took off the cover.