White mold or something else

[Rangeball]

My dad has a 12k g IGVL pool. He has globs of white stuff floating around in the water, not on top. My initial impression was it looked like someone threw toilet paper in the pool. Searching here seems to point to white mold/fungus.

I haven't tested the pool so can't give numbers. I did capture some of the larger globs and it isn't slimy, it almost feels like wet toilet paper, and while the smaller globs disintegrate when you roll them between your fingers, the larger ones will actually ball up into a roll like paper, and you can pull on both ends and it's pretty resilient.

Does this sound like white mold? I'm not thinking maybe some airborne organic, like cotton wood? Or maybe some little neighbor hood hoodlum did actually throw TP over the fence into the pool, except there's not cardboard roll to be found.

- - - Updated - - -

Forgot to add, he uses tri-chlor tabs for normal sanitation and di-chlor for shocking. No other chemicals. Other than the TP like stuff water is crystal clear.

 

[chem geek]

White water mold does look like and falls apart like wet tissue paper. He probably has too low an FC/CYA ratio since this mold does not grow in the chlorine levels we propose, though once established it takes a lot of chlorine to get rid of (similar to the way biofilms are much harder to eliminate than the individual bacteria that form them).

 

[Rangeball]

Thanks. I was over there last night towards dusk without the pump running and could see into his water much better. It's definitely mold/fungus. It's growing in the corners and seams of his liner. I told him last night that I suspect his CYA is sky high and we needed to blast it with bleach to get it under control, then take steps to lower CYA.

Hope to test the CYA level today and shock tonight.