Hi guys...new plaster pool...about two weeks old...and I'm now seeing white streaking from the walls down to the floor in just certain areas. In the picture below you can see it just above and slightly to the right of the shadow of my head (and down and right from the rope hook). I want to get ahead of this before it becomes a problem. Any idea what this is? Brushing the last few days has not resulted in any difference. Thanks in advance...you guys have been awesome so far!