Overflows. Internal or External

[AdamsB]

Originally Posted by sphelps

The only reason I see for this design would be a result from not being able to notch the glass/acrylic. It's just an external overflow without a notch resulting in the need for an additional internal box.

I agree. However I'd feel comfortable installing this overflow. I have no idea how to etch out glass for an overflow, which may not be hard but then confidence and correct tools are a factor. Also this can be used on rimmed tanks as an aftermarket install, like an undrilled 120 marine land. I'm not sure if they sell publicly or only install on their own tanks. I drilled my 90 for a small overflow box and considering that with a lid was $90 or so I'd rather fork out the extra "little" for this.