Stagnant water in Sump

[JCOLE]

I recently plumbed my tank to the garage with a sump set up(FINALLY). After a week or so now I see what looks like stagnant filmy water on top of each sump section. I was think of putting a couple air stones in each section to help agitate the surface. What do you all think? Any other ideas? I have heard of powerheads but trying to not make my ATO go crazy.

Thanks!!

 

[Flippers4pups]

I have the same situation as my sump is a 125 tank that I made into a sump. The first chamber where my skimmer is just sits and the last chamber where my return is does the same. My ATO float switch sits in the last chamber.

I’m able to get away with very small powerheads in each section to move the surface. Works for me.