Herbie and sump question

I'm having a issue wrapping my head around this and probably am overthinking this.


I have a 180 gallon with dual overflows that I will be setting up with the herbie overflow method and running return lines over the back. With the siphon drain sitting much lower in the overflow than a standard durso will it keep draining into my sump until it reaches the
the siphon or will it stop at the uppermost weir or only as much water is in the overflow box below the weir to the siphon ?

Again, probably overthinking this.

If I'm reading this correctly, you have a "reef ready" tank with a weir? If so, the water in the tank will stop at the bottom of the weir's teeth and the main siphon will only drain the water left in the weir. Hard to explain this without pictures but hopefully this helps.

You explained what I was explaining better than I explained. I understand your explanation perfectly. :))

Yes, it is a reef ready. 180 w/ dual overflow for 625.00, couldn't pass it up.

Glass or Plexi?

It is glass. I scare myself with acrylic, scratches and such.

You could also consider inline heaters like the hydor
300

I have dual overflows in my tank as well with herbie drains. Be sure to put a strainer on the main siphon and use gate valves on the main siphon drain line, ball valves are a pain on the Herbie system

suggest that you put a coupler on top of your main siphon stand pipe, it will let you fine tune the height, it makes a difference in how it flows/works, the easiest way to understand it is to experiment, but its not easy to cut and change the pipe height by small increments.