Setting Up A Sump Without Drilling

[sswm]

Hey everyone. Im looking to set-up a sump without drilling as my tank has tempered glass.

I have a 55 gallon main tank and looking to use a 20 gallon as the sump. I have found these overflow boxes My link and the water will drop approx 4' into the sump.

I need help on what size pump I will need in the sump to get the water back up into the tank and have things running smoothly.

 

[-Nemo-]

It depends on which overflow model you go with, the chart lists how many GPH each model is. I would probably go with the 600gph one, especially if you have or are planning to have corals. The rest of the GPH would be from powerheads.

If you get the 600gph one, you'll need a pump that can pump that much with the head loss of four feet. How much head loss a pump has varies by companies. I like magdrive pumps the best so i'll use them as an example. If you use a mag drive, you'd want the model 9.5, because it pumps 800gph at 4 feet.
Don't forget to plumb in a bypass with a ball valve so that you can turn down the pump as it will be pumping more than your overflow will be flowin down.