Reefer 250 filter cups postioning?

[Aeb1419]

Im using the red sea filter cups with filter floss. I notcied that some water doesnt actually go into the cup but around the sides of the cup and falls down the sides instead. I notcied the cup doesnt sit firmly against the holder. Is this normal? I was thinking of creating a gasket so that this wouldnt happen. Does anyone else experience this?

 

[OctaviusBrine]

I did notice that before I switched to a reef mat. I think it’s a flaw in the design because it is removable. If you don’t plan on getting rid of the socks you could use some saltwater safe silicone to keep it from going over the sides by the glass.