Well, I installed a Hayward SWG last month and just had it to the point where the FC was dead on 3 ppm day in and day out. So I started measuring FC less frequently (every 3 days). I had a leak in the PVC pipe and temporarily took everything apart to fix the leak. Then after 3 days, I had a green pool bottom. I forgot to plug in the Hayward flow indicator and the SWG won't produce Cl without a flow reading.
I just vacuumed and brushed and spiked it to 24 ppm FC with 60 CYA. And put DE in the sand filter. Looks a little better today, but still cloudy.