transitioning from glass holes open drain to herbie

[bluerrpilot]

The herbie system was never designed to be a self regulating system... never... people simply over the years have tried to make it more like the bean system...the Herbie system was designed to make "reef ready" tanks more safe, and quite. As the op stated, there is a chance of having a snail crawl down it if there is water in it. It is supposed to be a dry emergency drain. If you wanted a self regulating system you should go with a bean system.

So no, the open channel has nothing to do with the water height, as it should literally never be used...

I could be wrong but im pretty sure that both water and air is supposed to flow down the open channel in both the Herbie and Bean methods. The bean has the addition of the emergency drain which would not

 

[NanoReefWanabe]

If you are running a siphon system then you should have a dry emergency... the herbie system does not account for residual flow, and is not self regulating. People however like to play with your and have gone about using the emergency as a residual drain line not understanding the impacts it can have. To each their own...