Need sump help please

[Knr499]

I am using a Bashsea 30-14-16 biofuge. Pictured below. Also using reef octopus classic 150 internal skimmer. My issue is water level in fuge area. If I keep water level below adjustable gate (area marked in drawing) water flows great, but fuge area water level is too low. When I bring level up onto adjustable gate area it actually pulls water back under gate into skimmer section and flow diminishes in fuge section. So my deduction is either I need to seal adjustable gate or is my skimmer to big and causing a vacuum.

 

[Snoopy 67]

Put the adjustable plate on the other side of the mount & pressure will hold it against the wall.
Hopefully anyway.

 

[Knr499]

Put the adjustable plate on the other side of the mount & pressure will hold it against the wall.
Hopefully anyway.

I can’t believe I didn’t think of that! Bit of over thinking maybe, lol. I will definitely start there. Thanks.