Ahh I know the feeling.
sump
n.
1)A low-lying place, such as a pit, that receives drainage.
2)A cesspool.
3)A hole at the lowest point of a mine shaft into which water is drained in order to be pumped out.
The crankcase or oil reservoir of an internal-combustion engine.
In this hobby, a sump is something that holds water fed from your main tank and a lot of your hardware such as filters and heaters that used to have to be in your main tank or hanging on the side. A sump usually sits below your tank in the stand. The water is pumped back to the main tank via an external or internal pump.
Just about anything watertight can be a sump. My last one was a 10 gallon tank.
God, I thought this was an easy one!
Matt
