Dark stuff - bottom of pool

[Dpooltest]

My pool was opened last week, I am pretty sure that the debris on the cover found its way into the the water, but can't confirm. I spent a few days shocking the pool, vaccuming (pool was a little cloudy, and middle had pile of leaves), then backwashed my sand filter and added dry CYA. Water is clear, OCLT are good, no CC, but little piles of black dirt / bacteria? are accumulating (mostly in wrinkles of liner). I vaccumed two days ago, everything looked clear and the next days spots were back. What is this, and how do clear / clean? Is it safe to swim in?

 

[Dpooltest]

Best pic I could get

 

[Woodstock1234]

I just opened this weekend and I have this too, but a lot more. A bunch of stuff from my cover went in the pool as I was taking it off. My guess is I have algae. I'll be slamming this week.

 

[Tiredofpool]

My pool was opened last week, I am pretty sure that the debris on the cover found its way into the the water, but can't confirm. I spent a few days shocking the pool, vaccuming (pool was a little cloudy, and middle had pile of leaves), then backwashed my sand filter and added dry CYA. Water is clear, OCLT are good, no CC, but little piles of black dirt / bacteria? are accumulating (mostly in wrinkles of liner). I vaccumed two days ago, everything looked clear and the next days spots were back. What is this, and how do clear / clean? Is it safe to swim in?

 

[Tiredofpool]

I have that too. Spots disappear if touched then reappear later. Won’t vacuum out

 

[Chevydude057]

Did you ever come up with a resolution? Mine is 100% a filter hardware problem, so I'm stuck this year buying a new filter if I choose to open the pool.