Completely random citric acid question

[Tangdora]

Completely random question. Left a cleaning tank filled with citric acid out for a week after cleaning parts last week. Went to dump it tonight and it had this wicked surface film on top which was as thick as a thin wash cloth. Curious if anyone knows what causes this and what exactly this stuff is.

 

[EnterName]

Mold or some form of pellicle I suppose?

 

[PapaFishRocks]

Something I would NOT be touching with my bare hands!

 

[WildOne]

Thats a sporulating mold. The powder that was on top is spores, meant to get airborne, and the thin coat under is mycelia, often in combination with bacterial biofilms. There was a lot of organic matter in that container. You'll get the same by forgetting a cup of juice on the counter. No need to ask how I know.