lots of small particles in water in the late evening?
 

Does anyone else run into this problem? It seems to only happen in the late evening. Is there changes in the water at night? I've only heard ph changes but that's it.
I'm considering adding a in-line filter to my sump. Would anyone have any other solutions? :question:

Can you add some info about the tank? Age, contents, chemistry? Doesn't sound like anything too serious.