Hi, My name is Allen. I have been reading here for a while trying different things to get my pool back to normal. I have a 20,000 gallon inground salt pool with vinyl liner. I have a 1hp hayward super pump. Circupool RJ30 salt system. The output of chlorine is 1.5 lbs/day. Our system runs from 7a-7p. I just replaced the cell 2 weeks ago. The old one was end of life, it was worn and plates were deteriorating. We put new filters in around memorial day. I have a clear solar cover on the pool. While we were waiting for the new cell to arrive, we used power powder from lesile pool, to keep chlorine and help get CYA in the pool. We have been having trouble with keeping chlorine in the pool and with algae. Our CYA has been almost non-existent until about 3 weeks ago. Finally we got it up to 60, but still can't hold chlorine. The ph is 7.2-7.4. Hardness is around 200. Salt is 3100. Alkalinity is 140. All of our levels are normal except chlorine. We just can't keep it in the pool. The highest it has been was 1-2 last week after I tried SLAMing the pool. Now it's back to 0. Algae comes back within 3-4 days. The liner gets very slippery, have some green algae in crevices and where there isn't a lot of water flow. Every time we get algae we put shock and algaecide in, put in the vacuum and pull the filters to spray them out then spray with chlorine solution. I'm not 100% about the phosphates, I think it was 1-200 when we got it tested. I'm going to take a sample to the pool store tomorrow to get it tested again. We don't get a lot of debris in the pool, but if we do, we skim it off or out and put vacuum in. I'm getting to the point where I just want to drain the pool and make it a skate bowl. We have a basic liquid test kit that I use almost every other day, to keep an eye on things. When I get it tested tomorrow, I'll post the results. Thanks in advance for your time and any advice you may give.