herbie setup

[Myka]

Originally Posted by byee

Just wondering if there's a rule of thumb when setting up a herbie overflow - the drain pipe and emergency overflow pipe.

There's a 4" difference between my drain vs emergency overflow pipe.

The required distance is a direct relation to how much flow there is. The main drain needs to be low enough that it doesn't create a vortex at the surface and suck air in. I make the main drain as high as possible. The lower it is, the more water drains to the sump when the return pump is off.