Sump

[liquid_wind]

I recently read that a Sump with a weir is better than a overflow only sump. What is the difference?, and why is it better?

[Playa-1]

I think the idea is that the water crashing down on rock rubble in the wier box helps to oxygenate the water better also the wier box may help to keep from disturbing a deep sand bed.
I think its more practical if you have more of a deep sand bed and/or heavily planted sump/fuge without a skimmer.

I think with a system where you have a filter sock, skimmer, fuge w/ Chaeto and rock rubble then a wier box is optional if not obsolete.