Okay....I've been trying to rid my otherwise clear pool of this stuff:
I assumed it's algae, but now think it may be scaling.
I shocked the pool to an FC of 28 for the last 24hrs. I had the FC up to 16 for 24hrs before that. I tryed to brush the pool this morning and the stains/algae wouldn't come off. The last time i was swimming I tried a stiff brissled brush and some elbow grease. A few of the stains broke free and others remained. The texture is hard and feels a bit like high grit sandpaper. I tried to make a mark in it with my fingernail as well....to no avail.
This morning's water tested as follows:
The fill water (rural well water):