Help with overflow configuration.

[HornetMech242]

I am going to use a two darts for the flow on my 240. One on a CL with OM 4 way and one as the sump/fuge return. The pump is rated at 3600GPH so I calculated the overflow for 4000GPH and I need 60" of linear overflow space. I was thinking that two overflows would be needed, both with two 1" drains and one
1 1/2" return so I can plumb one dart through each. What would be the best dimensions to make the overflows that will minimize interference with aquascaping?

I am putting two 2" drains for the closed loop on the back glass, placement depends on overflow dimensions and placement. Tank is 72x30x25.

Thanks for the help.

Chris

 

[mflamb]

You only need one 2" drain for the closed loop. With head loss of about 5 feet the Dart will flow about 2600 GPH, so you will need much less linear overflow, and I would recommend two 1.5 inch bulkheads in each overflow, 2 for drains, 1 for sump return, 1 for closed loop return with the OM4way on top.

 

[HornetMech242]

I read on the closed loop there was no head loss because the tank provides water pressure on the drain. So if i make the overflows handle 3000 GPH then i only need 45" of linear space. So i was thinking 5x10 with the two 1.5 inch in each like mflamb has recommended. Do you think this will be good?

Chris

 

[mflamb]

Are you planning on supplying your closed loop from your overflows?

 

[HornetMech242]

The closed loop drain is going to be on the back center of the glass about 6" from the bottom. The only reason i was thinking two 2" holes was to reduce the amount of suction on a single drain. Should i do that or is one hole not too much suction?

Chris

 

[mflamb]

I have 2 closed loops, each with one 2 inch hole. Your Dart has a 2 inch inlet. Why do you need more than a 2 inch supply? You will have head loss on the sump return, so don't oversize your overflow boxes. They're hard enough to deal with anyway.

 

[HornetMech242]

Ok, i will go with one hole for the CL. For 3000GPH the calculator said i needed 45" linear so i will go with two over flows at 6x10 each with a drain a return in each. You posted in my thread about my closed loop and i seen how you had the OM plumbed above the overflow, im going to do that above one. The other i am going to bring the sump return through. I plan on using locline at first with the CL and return. I think i will have good flow for SPS.

Chris