Thank you for the responses! I do not have current readings today, it's been rainy the last couple days, so a shock is in order. However, I do get algae in the bottom of the pool in spots. After the shock the algae is on the bottom, dead. However I still see the green "cloud" on start up. I should also mention that my pump/filter cycles 24/7- only being turned off to turn the multiport to waste/rinse to eliminate water level. Generally FC runs between 2-4. My TA is slightly high at last reading-150, and PH is in balance. I am thinking however that the filter has channeled and the shock is not killing the older algae that might be trapped in it?