Overflow GPH Question

[nacl-man]

I'm looking into building a sump for my 44 pentagon corner tank, what GPH rating should I look at as far as an overflow box is concerned?
Thanks!

 

[broomer5]

700 gph is pretty common, and would work well for your tank IMO.

 

[nacl-man]

The LFS has one for 62.00 that they say is about 600... do you think that would work?
With about a 6 to 7 foot return line I was thinking about a MAG 9 (950GPH)? Any (aside from the long return line, I have no choice about that) comments?
Thanks

 

[broomer5]

A Mag9.5 may be too much flow rate. It all depends.
Is your 6 to 7 feet return line a vertical measurement, or total length ( vertical + horizontal ) ??
Although horizontal pipe runs, elbows and other restrictions are important, vertical height is what we're are most concerned with when selecting pumps.

 

[nacl-man]

vert height is only about 4.5 feet... is that all that should be taken into account when figuring on flow rate for the return pump?
Thanks Broomer5!
Cheers!

 

[broomer5]

The vertical height will have the most impact on your flowrate, but elbows, turns, tees, reducers and valves will also reduce the flow to some degree.
Horizontal runs do reduce flow, but not near as much as vertical height.
Can you sketch out or describe the returnline ?

 

[nacl-man]

Rough sketch of the plumbing system.... actual measurments are much less than I originally thought! I was just a little concerned as this unit is going to be off to the side of my tank (due to space restrictions and loaction of the tank), not directly under it.

 

[broomer5]

Seems to me you are right on the edge of using a mag9.5
I'd you'll have somewhere around 8 feet of head total loss, if you're using 3/4" pipe for the return.
Maybe a little more or less.
You could always get the 9.5 Mag, and place a tee/valve on the return line to redirect any excess flow back down to the sump.

 

[broomer5]

sorta like this

 

[nacl-man]

Thanks for the replies! I think what I'll do is get the mag 9.5 and dump the excess back to the sump via that tee valve. That'll give me something easy to hook my 3/4 flex water change tubing and some flexibility in the future (fuge, Ca reactor... who knows were this will go...).
edit: I just saw what you posted... is my check valve idea not the same concept? I noticed you put two regulating (i'm asuming that is what those are) valves on the return... i think i just got confused (sorry it happens pretty easy!)
Thanks again!
Cheers!