external Oflow return Q?

[AMD30]

i am planning a 10ft by 5ft by 30in tank and would like one short end have a 4ft external overflow.

How do i return the water? thru that over flow box? or outside of it next the side of the of OF?

i want the return to be on the opposite side of the OF.(about 9.5ft away!)

i have been trying to find build threads with external overflows but havent see much detail on how they return the water?

thx
tony

[Elliott]

tony, not sure what you are asking exactly. overflow will feed your sump, sump pump usually returns near the surface of the display, split into several arms to distribute evenly and create a chaotic flow pattern. it's not necessary to have your overflow and return on opposite ends because the overflow takes away organics that are bound to the air/water interface, while the return line brings "conditioned" water back from the sump under the surface. don't forget to drill a small hole just under the surface of the returns so they don't back siphon.

[AMD30]

oh ok, well i was thinking that i should have the chaotic flow on the opposite end of the overflow just so it would have a flow going back towards the overflow.

but my main concern is what the return line should look like and if the actually plumbing should be inside the external overflow or if it should be outside of the external overflow?

does that make sense? seems hard for me to type exactly what i'm picturing in my head.

[Elliott]

your mailbox is full

don't worry about your return line at the opposite end of your overflow, the overflow is taking surface organics away that are bound to the air/water interface, a totally different mechanism than flow.

use your return lines to create chaotic flow in the display by branching out in an opposing array over the tank, just below the water level

[AMD30]

i would like about 4x my display (800x4=3200gph) what size holes should i use and how many?

also wouuldnt the pan250 be to small for my returns?

are there any other pumps besides the panworld250(1900gph?) that have over 3000gph that would be educator friendly?

[Elliott]

my pan world 250 runs 4 eductors quite well, in fact I have to turn it down a bit on the output valve because it's too strong, and my sump is 50 ft away!

take a look at the head pressure curve:

http://www.panworldamericas.com/PS/50Hz/A3400477.pdf

if you want to run more volume then I'd run two of these pumps, that will give you a back up pump in the event one goes down.