Weir/sump question

[CheekyAl]

Hi, I'm looking into having a sump when a go over to a marine tank. Please forgive me because this is new to me.

My question is rather than have a weir or overflow box to feed a sump, is it possible to have a standpipe that sits just below the surface of the water and then goes straight down through the bottom of the tank to feed the tank?

My understanding of a weir/overflow box is to feed a sump but also to hold the main tank water back should the return pump fail. Is this correct? So by have the standpipe below the surface means that only a small amount of water would overflow into the sump

 

[David S]

thats basically it,but the amount of water going down the pipe is governed by the return pump flow rate.

 

[mfdrookie516]

The basic conecept it that only the water from that sump that is pumped back to the tank will overflow... so if you turn off the return pump, your tank will only overflow the water that was pumped to it in the first place.