View Full Version : 275G DIY Overflow Advice

03/30/2017, 05:43 PM
I picked up a 275G acrylic tank that is not drilled nor does it have any type of overflow system. The tank dimensions are 8'x36"x18" with 2" wide 3/4" thick euro bracing and (5) 3/4" cross braces. I am trying to figure out the proper dimensions for a DIY internal overflow box for a bean animal setup. The overflow would have to stick out at least 6" from the back panel ( ecause of the 2" euro bracing) in order to get enough room for my hand do fit down inside the overflow for setup. I am concerned about the amount of water that will backflow to the sump in the event of a power failure and I am trying to figure out the Best way to plan for the sump size. Any advice would be greatly appreciated.

03/31/2017, 02:00 AM
You seem to be confusing your terminology. If it is to be an "internal" overflow there would be nothing sticking out. Sticking out would be an "external" overflow.

A good place to start would be to determine how much flow you want from your sump's return lines. Usually people aim for 5-6x display tank volume. That will help you figure out what size pipe to use. The size of pipe will determine what size of bulkheads are required in the bottom of the overflow box. The type of drain (herbie, durso, bean animal, etc.) will determine how many bulkheads at the bottom of the overflow are needed. That will tell you how big the box of the overflow must be.