Your chorine is low and algae has probably formed. Your PH is good for a SLAM. Can you get liquid chlorine? Perform the Overnight Chlorine Loss Test linked below before you determine what might be happening. With only that test kit you are flying a bit blind because you need to know your CYA level too. Pool Care Basics FC/CYA Levels PoolMath Overnight Chlorine Loss Test SLAM Process
Welcome to TFP! For a wealth of pool care information please check out our free Pool School. If you are in need of specific help then we encourage you to Register and ask us here in the forum!