Overflow Boxes for Aquariums

An aquarium overflow is a necessary part of an aquarium sump plumbing kit. If you want to run an aquarium sump but don’t have a reef ready aquarium, or a drilled aquarium, then your aquarium sump plumbing will need to include an overflow box (we also sell overflows for drilled tanks). The overflow box hangs on tank. The inside half is a surface skimmer that draws protein rich water from the aquarium. A siphon establishes water movement. On some overflow boxes, an aqua lifter pump helps to create or reestablish siphon after power outage.

The external half of an overflow box is a gravity drain that sends water to your sump via an aquarium drain hose. A return pump then delivers water back to the display aquarium. As the water level rises inside the display aquarium, it cascades into the overflow box, completing the aquarium overflow plumbing loop.
29 Results
Tom Aquatics Aqua-Lifter Dosing Pump

Tom Aquatics Aqua-Lifter Dosing Pump

CPR Overflow Sponge For CS90, 100, 102

CPR Overflow Sponge For CS90, 100, 102

Tom Aquatics Aqua Lifter Suction Pre-Filter

Tom Aquatics Aqua Lifter Suction Pre-Filter

Marine Depot Overflow Box Nano

Marine Depot Overflow Box Nano

Marine Depot Overflow Box OF-800

Marine Depot Overflow Box OF-800

Marine Depot Overflow Box OF-300

Marine Depot Overflow Box OF-300

Marine Depot Overflow Box OF-1200

Marine Depot Overflow Box OF-1200

CPR 1-1/4 inch Drain Hose

CPR 1-1/4 inch Drain Hose

Eshopps Overflow Box Eclipse - L

Eshopps Overflow Box Eclipse - L

CPR CS102 Overflow Box

CPR CS102 Overflow Box

Eshopps Overflow Box Eclipse - M

Eshopps Overflow Box Eclipse - M

CPR CS90 Overflow Box

CPR CS90 Overflow Box

Marine Depot Elite OverFlow Box w/ Holesaw Drill Bit - Small

Marine Depot Elite OverFlow Box w/ Holesaw Drill Bit - Small

Marine Depot Elite OverFlow Box w/ Holesaw Drill Bit - Large

Marine Depot Elite OverFlow Box w/ Holesaw Drill Bit - Large

Marine Depot Elite OverFlow Box w/ Holesaw Drill Bit - Medium

Marine Depot Elite OverFlow Box w/ Holesaw Drill Bit - Medium

CPR CS50 Overflow Box

CPR CS50 Overflow Box

CPR CS100 Overflow Box

CPR CS100 Overflow Box

Eshopps Overflow Box Eclipse - S

Eshopps Overflow Box Eclipse - S

Xaqua INOUT Overflow Box and Return - Marine Water

Xaqua INOUT Overflow Box and Return - Marine Water

CPR CS202 Overflow Box

CPR CS202 Overflow Box

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