Hi all - Lets get you some background here. I've had this pool for 31 years (seems like forever). New filter 3 years ago - new pump this year. New liner 6 years ago. Kids used to use it all the time - I never use it. Anyways.. It was used all the time when the kids were growing up - now since they are out of the house, I have to open it because it is all of my back yard. Wife uses it occasionally. Last few years I battle with algae. Not so much green water - it grows on the walls and seems to be a dust of it on the bottom. I can see it clearly - so the water usually isnt bad. I brush the walls - case of shock after dusk, run the filter and by the next day it looks great. Trouble is, three days later it starts to form. A trip to the pool store will leave me looking to remortgage the house. After some research, I wound at this site and the help seems to be genuine. I check the chlorine (usual drops test kit) and it is good. I never used stabilizer... Which after a little reading - I'm guessing I should be. I do backwash on a regular basis, especially after a bought with algae. I do disassemble the filter and wash it out once during the summer. Does the fact that there is what I would refer to as 'inactive water" effect this? (What I mean by that is, nobody walking on the bottom, churning up the water) I know of so many people in my area with this issue - even brand new pools with plenty of activity. Aside from a few dump truck loads of dirt - I hope I can get this under control once and for all this year. I read a few ways to do the stabilizer - skimmer basket / sock filled with it ~ my trouble is, I will need a lot. I have close to 50,000 gallons of water to treat - If I need 10 or more pounds, how will it all dissolve? I do appreciate any help offered - many thanks!