SOLVED: Black sticky mystery goop in skimmer

wgipe

Gold Supporter
Jul 4, 2020
512
Fletcher, OH
Pool Size
20000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Thought I'd post this in case it helps someone in the future.

Since opening the pool this spring, I've been battling the mysterious black sticky greasy residue at the water line in my skimmers that appears to be plaguing some others here from time to time. Of course when it showed up, the first thing I did was search here for a solution. It didn't seem like there was ever any conclusion as to what's causing it or what to do about it - theories ranging from oils/lotion, polymer coming out of a liner, RV antifreeze or Polyquat breaking down from winterization, etc.

After getting tired of swapping out tennis balls and wiping down skimmers every few days, I finally just decided to SLAM it and see what happened. It's now been about two weeks - the tennis balls in the skimmer still look brand new and I've not seen any residue at all on the skimmer walls. I'm still not sure the cause, but it would sure seem it was organic.

I should add that I didn't think it was necessary to run up to SLAM level when I opened because my FC was still above minimum and water was crystal clear on opening. I now think that may have been a mistake. Should it be standard practice to SLAM or at least do an OCLT on opening from here out? Pool was new last year, so this was my first opening.
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.