I have a very green and cloudy pool. I have been going to the pool store 3 times a week for about a month now and have spent far too much money on chemicals that have done absolutely nothing. I have a pool guy who say the flow and filtration are good and just keeps adding more shock. I知 so over the pool at this point and need help. I have 20,000 concrete pool with a cartridge filter. It is chlorinated and 8 feet deep at one end. Thanks for any help. I知 at a loss and feel so helpless.