Any Idea What Is Floating In My Pool?

[MBMMPool]

9 Year old vinyl pool with variable-speed pump (replaced 2 years ago), original sand filter, and autocoder (replaced earlier this year). Water has always been clear, with TFP guidelines followed for life of pool (only liquid chlorine). Only thing slightly out of the ordinary for us this summer was quite a bit of sunscreen in the pool (my 19 year old daughter taught swim lessons over the summer, and parents really like to lather/spray kids up these days!). I gather this is the case, since I noticed some visible oils/suds- usually just after opening autocoder. Anyhow, after not so much use over 1.5 weeks, I opened & closed the autocoder a few times over the weekend- and gelatinous thin clear particles seem to be floating "Everywhere". Some of the larger pieces have a defined "web" pattern (circled in YELLOW) on picture, but I've never seen this before and would love any advice. I have two potential theories:
1. Sunscreen on surface of water is clinging/bonding to autocoder, and being released when opening/closing?
2. Something internal to the Sand Filter?

Any help/suggestions appreciated.

 

[Texas Splash]

Not sure if it's clinging to the cover (perhaps), but I like the sunscreen theory in general. Water is so clear the first thing I focus on is the drain. We can't see your Poolmath logs, but have you tried increasing the FC level a bit just in case the water needs a bit more help breaking down that substance?

 

[MBMMPool]

Apologies for not responding sooner- Thank you for the Quick feedback. I went ahead and SLAM'd with a 2.5G tote of chlorine I had on hand Monday evening, and let the pump run more than normal with the cover Open all day Tuesday. Whatever the material was, the chlorine appears to have cleaned it up (noticed some yellow "powder" in some places on pool surface, but that also seems to be subsiding. Measurement today indicate some rapid consumption of chlorine as I was down to normal around 4 FC this morning. pH is at 7.8, TA 170, and my CYA was <20. I went ahead and added 2lbs of CYA (all I have on hand at the moment), and will continue to monitor (and be a bit more diligent with my daily chlorine checks). Hopefully, this does the trick.

 

[Texas Splash]

Sounds like you're on the right track. If in doubt later about excessive FC loss, feel free to do an Overnight Chlorine Loss Test.