Oily film on surface of RO/DI water

[Nate_Krohn]

Over the past two days I’ve noticed a thin and spotty film on the surface of my RO water. Any idea what this is and will it hurt my livestock? I’ve been removing it just by putting a strip of filter pad while mixing water.

 

[reef lover]

Is this in your holding bucket?
What type of container ?
How long since you changed your filters?
Any other organics getting in there?