Overflow box empties to fast.

[Relect]

Restricting the inlet of your pump will cause premature wear on pump but shouldn't on outlet side.

[Aquattro]

You simply need an air hole at the top of your plumbing. Don't restrict anything. Look up durso design, it shows how to use a hole with a valve. I don't use a valve myself, just have a small air hole in the top of the stacks (dual overflow pipes).

[subman]

post a pic of the setup.

[wickedfrags]

what he said

Originally Posted by Aquattro

You simply need an air hole at the top of your plumbing. Don't restrict anything. Look up durso design, it shows how to use a hole with a valve. I don't use a valve myself, just have a small air hole in the top of the stacks (dual overflow pipes).