Sump

Definition

A sump is a secondary aquarium plumbed below the main display, typically holding the protein skimmer, return pump, refugium, heater, and supplemental media. Sumps add water volume (parameter stability), hide equipment from the display, and allow easy media changes.

Practical use in aquariums

Sump volume of 25-40% of display volume is typical. Provide a baffle system to slow flow through the skimmer chamber, leave the return pump section as the only chamber that fluctuates with evaporation. Always plumb a teeth/strainer guard on the overflow box to prevent fish from getting sucked in.

How Sump fits the bigger picture

Understanding Sump matters because it's connected to broader husbandry decisions: equipment selection compounds: skimper + return + dosing all need to match each other and the tank size.

Browse the Fast Aquatics care library for full husbandry tutorials covering Sump in context.