Internal or hang on overflow

[jmurr8484]

I recently seen this video on youtube where this guy had and internal overflow but it drained from the side. Would that be more efficient and have a higher GPH reading than a hang on overflow that's rated at 800gph. If anyone have any experience, what are the benefits and drawbacks of both. Thanks

 

[BigJim]

The flow rate really depends on the pipe size more than anything.

HOB overflow
- Can be added to existing tank without drilling.
- Easily movable.

Internal overflow through the bottom
- Easier to hide than a HOB overflow.
- Simpler to plumb than a through the side overflow.

Internal overflow through the side
- Less likely to get blocked than an internal through the bottom overflow.
- More difficult to hide the plumbing.
- Theoretically should flow less than a through the bottom overflow of the same diameter due to slightly less head pressure. May not be applicable in real life.