A couple of weeks after opening, a co-worker of mine found this "stuck" to the sides of his pool and some on the steps as well. He described it as almost oily to the touch and that it was sticky and remained so a couple of days later. I have never seen anything like it.
I suspect it to be some combination of algae and residue from perhaps several types of pool chemistry thrown in at random.
The pool has been chlorinated heavily (30+ppm) at times with Cal Hypo but not regularly so FC could easily have been at zero more than once this spring.
His test results the day after this pic were:
FC = 26
CC = .5
pH = 7.6
TA = 140
CYA = 50
Obviously, the pool has been further out of whack in the recent past, but for now, things appear on the right track.
A 24 hour report after these tests were that this goo was going away slowly....water was and has always been fairly clear.
I am simply at a loss as to identification. It appears that shock level of chlorine will fix it but I sure would like to know what it is.