This has me baffled...My PH was a little high so I just added 8 oz of PH plus powder to my skimmer. About 2 seconds after the PH plus went in dark green water shot out the two return jets for about 5 seconds. Another issue I noticed that I didn't notice until last year is after I vacuum I have to immediately backwash and rinse. If I take the vacuum hose out of the skimmer without stopping and back washing green water will shoot out of the return jets. My pool is 8 yrs old, above ground, 12,000 gallons, sand filter (300lbs), sand changed 1 year ago, 1 1/2hp pump.
The water has been cloudy but my chemicals are ok. I just had my water tested a few days ago and everything was ok. I check chlorine and PH daily. No trees around and I back washed 5 days ago. When I back wash I never see the type of green water that just came out the jets. The water starts out clear when back washing, turns cloudy then clear.
Does any of this make sense? Why would green water shoot out of the jets when I put in the PH plus? Is my sand filter the problem? HELP! lol