We've been battling algae ever since we upgraded our pool equipment. We knew we might have some minor problems because the pump was off for several days while we plumbed a new pump, sand filter, and liquid chlorinator.
Sure enough, we had a little bit of green on the bottom of the pool. If you swipe the brush across it, it disappeared. So it must be algae, right? So we shocked the pool. Repeatedly. We've done regular shock and are currently at yellow mustard shock levels. No impact to the algae.
Here's the kicker. I'm not losing ANY chlorine overnight! And Ive never had ANY combined chlorine, day or night. Not even 0.5. I brush the pool everyday, and now, I have enough algae that it is gathering in small clumps at the bottom of the pool. We've been at it all season, but it just keeps getting worse!
The algae kicks up a cloud of light green when I brush. It's never turned grey or brown. What am I missing?
***edit: we are at 20 ppm CYA. I intend to bring that up, but I figured I would wait until we were done shocking. We've been shocking off and on for 2-3 months now, with no success.***