I have a 33 ft above ground pool. Every time I vacuum I backwash and rinse. I even leave the pump off overnight sometimes and when I turn the pump back on within minutes there is algae or something right back on the bottom of the pool. This waste chemicals, water, and my time. I have ask the pool guy what is wrong but he doesn’t seem to know or either doesn’t care. Any suggestions? Could there be algae in the filter?
There could be. It might be time to replace the sand or cartridge. It could also be in the plumbing. Have you tried an algaecide to destroy the stubborn algae?