I ditched the chlorinator a couple years ago and switched over to the BBB method, so happy! My pool is always blue, except for this "stuff" on the bottom of my pool. When I opened this year and before I started up my new SWG I thought it must be mustard algae. I took my pool up to Mustard shock level, 30PPM for 7 days back in May. Brushed the pool bottom every hour or two during the day and every night passed the overnight test running filter 24HRS daily. But, the "stuff" would come right back after 30 minutes of brushing. I thought I read that if it was mustard algae it would not come back until the chlorine dropped below mustard shock level, but it was coming right back. Not on the walls, always on the bottom. So, I assumed that it was Pollen. Once I got the SWG up and going I started running the filter from 8AM - 8PM. I noticed that after I ran the robot cleaner at night after the pump shut off the pool bottom would be clear and in the mornings the "stuff' would not return until the pump started back up.
What do you think?
If it was mustard algae, wouldn't it settle back on the bottom overnight without the pump running? When it's brushed it disappears but doesn't make a green cloud like algae does. I am in Western Kentucky and everyday since spring I get an iPhone app alert from The Weather Channel that pollen is high in my area.
I replaced the sand in my filter this year, thinking maybe it was channeled and not working properly. I have been using a filter sock and it catches alot of it. Below is my most recent numbers.