Difficulties achieving positive pressure with Fractal North

So I built a new PC in the North case and I'm trying to get to positive pressure to avoid dust. I have two Be quiet pure wings 140 mm in the front and one Be quiet pure wings 120 mm as exhaust in the back. On idle, the air nicely flows out the back. The issue is when GPU fans are running, they start pulling in air from the back of the case at the bottom. Even if I run the exhaust at minimum RPM and the intakes at 100 %, the GPU fans still pull air in.

I was thinking adding top exhaust would probably only make it worse. Unfortunately I cannot add a 80mm fan at the bottom because of the GPU size. Should I just get stronger intake fans? Could static pressure optimized fans help?

Thanks for any tips!