My overflow box

My overflow box is 6 X 4 X 5 inches. How many gph do you think it produces? I bought it a long time ago so I dont have the name recorded anywhere. It almost matches perfectly with the pump, and I need to know how much the pump produces.

 

my best guess is 1200 GPH.

 

Aquarium Overflow 1200 GPH Overflow Box - Bulk Reef Supply

this one has the same dimensions.

 

Your return pump controls the flow rate, not the size of the box. You want your box to be able to handle at least 50% more flow than what your pump will be doing (IMO).

 

already have a pump but Im trying to find out how many GPH it produces. So you would say it produces 600 GPH?

 

Depends on how high the pump has to pump the water up

 

It really depends on the size of the U-tube(s) and outlet pipe(s). Water will have no problem getting into the tank side of the box, it is how much water the U-tubes can siphon that determines flow rate. My Eshopps box is 9"x3"x10", with dual U-tubes, and dual 1" bulkheads and is rated for 1000GPH for reference.

 

I only have one U tube.

 

Don't quote me on this, but if it is an 1 1/4" tube, it should be able to handle up to 800 GPH. I use one 1 1/4" U-tube on my setup, which flows around 525 GPM and it works great.

 

I think your best bet is to find the name/model of the pump and google search that. Then you can also get what it pumps at different distances.

Or stick your pump in a pail full of water and time how fast it fills another pail - that's how I tried to figure out the potential volume of my custom overflow.

Anything else is just a guess.