black slime like in skimmer

[madwil]

Are you sure your CYA is 100, or does it read 100 and could be 100+++++?
Most tests only go to 100, and you can't tell how much over 100 you really are...
This could lead to problems figuring out what FC to maintain.
As Watermom said, if your water is clear and no slimy spots, probably not algae in the skimmer

[airraid1999]

just got test kit and learning how to use the kit it is at 80or lower by sticks defiantly not higher keep in mind i did a complete water change due to a liner change and this was the last week of apr. so i have been getting all levels to where they should be as i said just bought the kit so really learning how to use that i used strips before i tested with strips today (due to lack of time i test every day with strips) and the free chlorine was only thing that was high will do another full test tomorrow when liner was changed i added stabilizer so its been circulating 24/7 for about a month now as stated water is crystal clear just didn't understand the black in skimmer had allot of people over weekend so it very well could have been sunscreen and etc. had this every year store said algae but not seen anywhere else but in skimmer i don't think its algae from what i read on this forum this is a great site!!!!!!!!!!! thanks

[PoolDoc]

If you have what we used to call "slip and dippers" -- folks that grease up, lay out, sweat and sun, rinse it all off in the pool . . . and then repeat, you will DEFINITELY get a slime line in the skimmer, and often on the pool tile or liner.

Best thing to scrub it off with -- that will not mess up pool chemistry -- is baking soda paste.

Ben