I have a 22 x 5 above ground Intex pool. I bought it last year and had fair success. I’m not having such luck this year. I have a new sand filter and salt water pump. I began by shocking, which seem to be working. Then went out of town for a few days. Came back to a very green pool. I began shocking again. No change. I took a sample of the water to a pool store. They could find no issues with the water. He also told me that with those pools (the cheap ones :-), I may just need to drain it and start over. I really don’t want to do that! I have tried shocking again and was planning to add some algae. Would appreciate any ideas. Thanks!
Try an algaecide in addition to the shock. Many of these chemicals advertise a "green to clean" promise and should assist your chlorine in clearing up the pool.