All summer my pool has been very healthy! But three days ago I tested and had no FC. I noticed a light green coating on my white steps. After removing the solar cover, the deep part of the pool was also greenish with algae stuck to the liner. I have been shocking it now for three days. My latest measure was 60 CYA and the recommended 24 FC for shocking. The water is again clear, but I am getting deposits on the bottom of the pool that look like clumps of dirt. When hit with the broom, the clumps disappear in a small cloud of brown/green. I am hoping this is the dead algae that will have to be vacuumed out once I pass the overnight FC loss test.
All Summer I have maintained the pool at 4 to 7 FC. I did notice similar clumps on the bottom during the summer. They reacted the same way when hit with the brush. We thought it was dirt being blown in to the pool. I now believe that I may have had a slight algae bloom at the low end of the FC, and then killed it at the higher end, causing the dead algae on the bottom. Does this sound right?
My skimmer obviously won't remove much from the bottom, so is it safe to use my Hayward cleaner with a shock level present? Or should I wait til I pass the overnight FC loss, drop down to normal level, and vacuum.
As always, thanks in advance for all the help!