My pool was opened last week by a company I hadn't used before. It's always dirty when it's first opened but clears up in a few days. I put the bot in to clean it and ran it several times. Once all the big stuff was gone, there was still some fine black debris in the places where the walls meet the bottom. I decided to brush it all to the bottom and then vacuum it manually.
By this time (yesterday), the water was sparkling clear and the pool looked great except for that gunk in the corners. But when I started to brush, I realized it was dirtier than it looked. Each push of the brush brought up clouds of fine black debris and once areas are brushed clean, it's obvious how dull the liner looks in the rest of the pool. After vacuuming, the pool looked great but later on I realized I missed a few spots.
Today, it's as if I never vacuumed it. Is this algae? It's not green, it's black. When we've had green algae in the past upon opening the pool, it always goes away with some brushing and a few days of running the filter.
I don't have a good test kit although I did order one. The cheapo test strips I have say the pool chemistry is perfect!
I don't know how to make a signature so here are my pool stats:
In-ground, vinyl liner, 16,000 gallons, Haywood Pump, DE filter, Polaris automatic cleaner