Overflow design question

[cartery]

I was thinking of installing an internal overflow box and I started wondering... What's the point of a box, either internal or external? Why not just have an internal weir that covers the holes that go directly to the drains? I tried drawing an example assuming a Herbie drain style, but I bet it would work with a Bean Animal, too.

 

[KrisReef]

The weir determines the depth of the drain into the sump. The top of the box sets the level of water that can flow into the drain.

 

[cartery]

The weir determines the depth of the drain into the sump. The top of the box sets the level of water that can flow into the drain.

I'm not sure what you mean about the depth of the drain. Don't the teeth of the weir determine the water level?

 

[UncommonSense]

Why not just have an internal weir that covers the holes that go directly to the drains?

Gravity drains perform far more reliably when oriented vertically, vs. horizontally!

You can help yourself out by using a spigot elbow as both drain inlets, but this exact design was hard to tune for silent operation in my early years of experimentation… (the sump in my tank thread was my old DT, with an acrylic box bulkheaded in place on the left side… now, the tank just has plugged bulkheads in it to seal the old drain holes…)

 

[cartery]

Why not just have an internal weir that covers the holes that go directly to the drains?

Gravity drains perform far more reliably when oriented vertically, vs. horizontally!

You can help yourself out by using a spigot elbow as both drain inlets, but this exact design was hard to tune for silent operation in my early years of experimentation… (the sump in my tank thread was my old DT, with an acrylic box bulkheaded in place on the left side… now, the tank just has plugged bulkheads in it to seal the old drain holes…)

Gotcha! Thanks for chiming in. I was certain someone on here had tried this.

 

[RocketEngineer]

I was thinking of installing an internal overflow box and I started wondering... What's the point of a box, either internal or external? Why not just have an internal weir that covers the holes that go directly to the drains? I tried drawing an example assuming a Herbie drain style, but I bet it would work with a Bean Animal, too.

For any overflow you need an edge the water flows over to pull the oils/proteins/dust/hair that ends up in our tanks so it can be captured in the filtration of the sump. Then you need a pipe to the sump. Everything else is intended to make the setup quieter or easier to install.

Looking at that picture, my concern is the box doesn’t have enough of a gap to get the bulkheads installed properly. This is one reasons they tend to be several inches wide.