External vs Internal standpipe flow rate

[ulfius]

I'm trying to decide whether or not I should use an external or internal Durso standpipe in my aquarium. The LFS recommends drilling the bottom of my tank (acrylic not tempered, so I'm safe) so that I get more flow than drilling the back of the tank, but once you add a standpipe, doesn't that become a mute point because the standpipe becomes the limiting factor no matter the placement? I can see if there's not a standpipe that there might be more flow.

Here's a drawing showing both placements:

p.s. Am I asking too hard of questions? My last posts have not received any responses.

http://www.aquariumadvice.com/forums/f60/overflow-sediment-build-up-with-standpipe-117408.html

http://www.aquariumadvice.com/forums/f60/aquac-remora-modification-117242.html


TIA,
Shawn

 

[ezy33]

This question rates a definite maybe! I think not having to deal with drilling your stand may be the deciding factor.

 

[jsoong]

From what I know of Physics, I would say the 2 are the same.

Flow through the pipes varies with the driving pressure, and that would be the difference in height between the tank water level & the sump water level. In both setups, the height is the same, so I expect similar flows. <With or without the Durso.>

 

[CaptainAhab]

Other than needing to make sure you have the room behind the tank I don't see any difference. You're drilling your tank one way or another.. either back or bottom. Although with the external you get one shot at it, you can't adjust height after the fact. Well you can but that would be messy