Opened my pool later this year than normal. Somewhere around 1st of June. Pool cover had holes in it which allowed debris in pool. Had algae on bottom. Cleaned bottom of debris and algae on waste . Put enough chlorine in pool to slam it at night. Next morning it had 11ppm chlorine. Checked it when I got home from work and it was 0. So lost 11 ppm during the day. Chlorine is getting harder to get right now. So decided to add hth super algae guard. Did initial dose 3 days in a row. So algae should be dead. Pool is crystal clear. Everytime I add chlorine it is gone in no time. Ph is 7.2 and alkalinity is 50. I know it needs to be raised up. I’ve never had this problem before. Actually it’s the 1st problem I’ve had since going to BBB. Heard of chlorine lock but don’t know much about it. Stabilizer is low also.