S omething
U nder
M y
P laything
Had to do it . . . . . .
A sump is a way to increase your water column at the same time creating a place to put your equipment (heater, skimmer, filter socks, monitor probes, macro algae). It also provdes a place to put additional media, carbon, phosban etc as not to clutter the display tank.
Also makes water changes easier.
House