120 Gallon Progress

[vanreefer]

Originally Posted by mr_alberta

How are you drains plumbed? I only see 1 drain pipe going back into your sump?

What he said...

Did you join the 2 1" pipes coming from the drains
Did you use 1" pipe after join
If so the 1" pipe won't be able to handle the flow of 2 1" pipes

If the tank overflows when you open up the flow on your return pump the drains are being overwhelmed, 2 1" drains should be able to handle that volume

What are the linear dimentions of your overflow?

From Reef Central
Mag 18 at 4' head with 2 90's = Gallons per Hour = 1115

Drain and Overflow sizes are calculated as
Recommended minimum drain pipe diameter = 1.38 inches
Recommended minimum linear overflow size = 17 inches

HTH
Dan