I don't remember if you're using the pool yet or not. Perhaps you need to move to the +shock+ column of the chart. I recall reading that black algae can be very hard to kill and digs in to the pores in the surface and hangs on tight.

A couple other thoughts:
Is it still pollen season in your area? - might explain the green stuff in skimmer.
If the pollen is over and it's green(live) algae (wich clogs filters quickly), I'd guess that there's more CYA than measured or FC is dropping too low (Phoenix sun). Either way, my suggestion would be to raise the FC level to +shock+.