Pool is new this year, and for the first month or so, we were working on getting proper chemical balance. We're just about there now; fine tuning CYA and then everything should be in line with TFP recommendations.
I've noticed that between the water line and top of the pool that I have a slight discoloration (Almost brown?) Hard to tell of the color on the blue pool, but it also continues into the light color skimmer and definitely brown-ish there. You can also feel it - the side of the pool below the water line is smooth, while above is not. It's almost scummy, but it doesn't come off. Tried rubbing it with a finger, brush, nothing. It's not bad, but I don't want it to get too far gone. VERY uniform around the entire pool at and above the water line.