Herbie overflow - what size?

[MikeInToronto]

Both the Herbie and the Beananimal work best with a coast to coast overflow. You want just the surface tank water to enter the overflow and you want it to "hug" the sides of the overflow as it goes in. Otherwise you have a very large volume of water being pulled through a (relatively) small overflow box. This leads to a lot of problems with fishes or other animals getting sucked over the weir, or it results in a loss of efficiency as the overflow no longer pulls just the surface water. Therefore, a properly set up overflow for a Herbie will be large enough for a Beananimal as well.

I would go 1" as a minimum for your open channel and 3/4" for your siphon. If you are going with 600 gph, I'd do 1" and 1" (and 1" for the Emergency if doing BAA).

[fkshiu]

The bigger, the better (within reason). Remember, a Herbie is designed to be adjustable downwards with the gate valve. It's much easier to fix if you've gone too big, than if you've gone too small.

[mark]

check out the calculator on Bean Animals site (here, towards the bottom) it basically show how much a siphon can flow so can be used to size a Herbie.

[Sunee]

Thanks everyone! I didn't realize the Herbie required a coast to coast overflow. I guess I have to go back and do more research.

[mark]

Originally Posted by Sunee

Thanks everyone! I didn't realize the Herbie required a coast to coast overflow. I guess I have to go back and do more research.

You don't need a CtoC for a Herbie (maybe for the Bean).

[Sunee]

Originally Posted by mark

You don't need a CtoC for a Herbie (maybe for the Bean).

thanks Mark, I really didn't want a CtoC overflow. Also, thanks for the link to the calculator it will help me with the pipe sizing.