Foolish question, maybe...
 

This is a really stupid question, but I just don’t know…

Okay, so I’m thinking ofchanging my 55 and 16 into one 25 gal. My tanks are okay, but neither one is like “wow”. I figure if I just have one, and really focus on it, it would be less work, and over all look better.

So, if I’m going to do this, I’m going to do it differently than my last two tanks – right the first time :)

As such, I want an overflow box in the tank. What’s the point of the “inverted U” shaped drain. Why not just a drain at the bottom of the box? Heck, wouldn’t that make more sense as water might stagnate at the bottom of an overflow box? And if not, why not just a straight tube up the middle of the overflow box?

Thank you all...

-Paul

*tagging along* :)

http://www.dursostandpipes.com/

Basically it's to control noise and water level.

Interesting... Thanks for the link!

The point of the U shape stand pipe is to avoid a vortex (whirl pool)
Which will cause a lot of noise.
The reason it's tall is, pipe is cheaper then glass.
If you dont have water in your overflow chamber the pressure on the chamber glass is high. If you got a leak you could end up with your entire tank on the floor in a few minutes.