I have one that has come to me this year after 3 yrs of "it is so easy, just throw the puck in the skimmer and call it good" talk................his pool is GREEN and his pump is acting up! Hummmmmm you think it is all of those pucks? Pushed your CYA up there AND they messed up your pump seals JUST LIKE I SAID THEY WOULD!! Gurrrrrr but he is ready to listen. I will go over on Saturday with my test kit. While he is cooking steaks on the grill I will test his water.....who wants in on just how high is CYA will be??? Yummmmmmmm easiest steak dinner I have ever earned!