Return pump size

[edwardclaxton]

What size return pump do I need for a 140 gal with 2 inputs of 3/4 in?

 

[Ingy]

Is the 3/4" inside or outside diameter of the pipe ?

 

[edwardclaxton]

Not for sure I got the pipes with a kit from glass holes.

 

[gravereaper0]

What's in your tank, how heavy is your bio load gonna be. Good rule of thumb is to be able to cycle your tank 4-6 times in an hour, but again, depends on your bio load. Don't forget to add the size of your sump as well when trying to figure out your GPH

 

[edwardclaxton]

Im going to have a mix between coral and fish.

 

[Ingy]

Although when planning the holes you take into account all the above factors, when looking for a return pump, you are limited to how fast the tank can drain. If the pipes are 1" O/D and 3/4" I/D then each will drain at about 600 gph max. If the pipes are 3/4" O/D and about 1/2" I/D then your combined flow will be under about 800 gph if memory serves me on that one.
The first is likely the answer as its a common drain hole size. So plan for about 1000 gph max return to avoid pumping out your sump faster than the drains fill it. Then you have to take into account head loss which is the difference between the water levels in the tank and return section of the sump. Pumps normally have a graph on the back of the box which shows rate vs head loss. Add 1' for each 90 degree elbow in the return between the pump and tank.

Whew. Good luck.

 

[TommyP]

If I have a overflow box with a 1'' drain to a 10g sump with a 700gph pond/aquarium submersible pump with 3/4'' out return back to the DT would that be okay?

 

[gravereaper0]

If I have a overflow box with a 1'' drain to a 10g sump with a 700gph pond/aquarium submersible pump with 3/4'' out return back to the DT would that be okay?

Yes that'll work. Flow rates are higher under pressure and the 1" intake will have no problem. Also depending on what else you're running through your return (tubing, elbows, chiller, UV sterilizer, etc.) Plus the overall height of the aquarium will affect your gph

 

[edwardclaxton]

Will a mag 18 work. It will be ran through tubing prolly 3/4. Have a T and it goes into 2 3/4 return at about 4 ft