Black spots on my cleaner

[jorgeL]

Has anybody seen black spots in their cleaner? I am wondering if it is black algae, I don't see it anywhere else in the pool, at least not in visible areas, just in the pleated seal of the cleaner. I can't even scratch it off.
FC: 5
CC: 0
pH: 7.7
TA: 125
CH: 1150
CYA: 140

 

[kimkats]

Well that is a new one for me! Here is a bump to get it in front of more eyes.