Hi. I’m a new pool owner, since June, I vacuumed the pool yesterday and it looked great. Today I see this round edges and in seams. When I touch it with my foot, it seems to disappear which is what made me suspect algae. I now believe I’ve had this for awhile as I seem to have to vacuum my pool a lot as it’s dirty. I blamed dirt as it’s been windy. My chemistry has been good. Just needing chlorine now and then. It’s always clear and blue. If it’s algae, how do I get rid of it?