Hello, I'm new to the site but have been doing a lot reading especially on the slam method. Long story short. My mother in law broke her hip and couldn't take care of the pool while she was in rehab...she is in Buffalo NY, with a 42000+/- gallon pool with vinyl liner and de filter, which is green since the fall of 2019. The pool was closed with it being green. I live in Florida with a pool that could swim in hers! So I've been helping her over the phone and utilizing neighbors for help. I bought a lot of powdered shock last year to keep adding to the pool to get rid of the algae. Pool store up there is not much help. I ordered her stop yellow algaecide (sodium bromide) to put in with the shock. I use it in my pool. And of course nothing happened. Kept adding shock and no change. Pool closed again green in 2020. This year I was able to get her liquid chlorine from a different pool store. Sent up 4 bottles of suncoast stop green algaecide which is edta. Added 20 gal of liquid chlorine in 48 hours with pump on recirculate as was told to do by my local pool store owner. No change. Pump runs 24/7 during the season. She still adds her daily cup of powdered chlorine in like she's been doing for past 40+years. Found your site and read about the Slam method. I want to try it but don't know if it will work since the pool has been green for so long. The pool will be closed up end if september for the winter. I really hope we don't have to drain the pool. I'm ordering her the tf-100 test kit. So any advice will be much appreciated because I'm at my wits end. Thank you for your time.